Archive for the ‘Biotechnology’ Category
In a side-by-side comparison, a noninvasive, multitarget stool DNA test proved to be more sensitive than a fecal immunochemical test (FIT). This result, published March 19 in the New England Journal of Medicine, suggests that the DNA test, which includes quantitative molecular assays for genetic abnormalities related to cancer, could significantly improve the effectiveness of colon cancer screening.
The FIT test detects hidden blood in the stool, a potential signal for cancer. In contrast, the DNA test includes quantitative molecular assays for KRAS mutations, aberrant NDRG4 and BMP3 methylation, and β-actin, plus a hemoglobin immunoassay.
The effectiveness of the DNA test was established in a study that evaluated nearly 10,000 asymptomatic patients who were deemed to be at average risk of developing colorectal cancer. It turned out that 65 (0.7%) of these patients had colorectal cancer, and 757 (7.6%) had advanced precancerous lesions. When these patients were screened, the study determined that the sensitivity for detecting colorectal cancer was 92.3% with DNA testing and 73.8% with FIT.
Posted March 18, 2014on:
The final cost of the Human Genome Project has been estimated at approximately $2.7 billion. At the time, researchers predicted costs would need to fall significantly to enable routine genome sequencing and usher in a new era of personalized and predictive medicine. In late 2001, at a scientific retreat convened by the National Human Genome Research Institute, the threshold cost of $1,000 per genome was conceived. Consequently, the “$1,000 genome” has been chased by DNA sequencing platform developers ever since.
With the recent launch of the HiSeq X Ten system, Illumina appears to have breached the $1,000 barrier to sequence a human genome in a single day. Illumina’s “$1,000 genome” claim is inclusive of instrument depreciation, consumables, DNA extraction, library preparation, and estimated labor. Although the exact cost is widely debated, this indicates a “real-world” figure rather than an abstraction of direct sequencing costs. In this context, it would appear that the personalized medicine era envisioned in 2001 has officially arrived.
Perhaps you’ve punched out a paper doll or folded an origami swan? TED Fellow Manu Prakash and his team have created a microscope made of paper that’s just as easy to fold and use. A sparkling demo that shows how this invention could revolutionize healthcare in developing countries … and turn almost anything into a fun, hands-on science experiment.
In biology, scientists typically conduct experiments first, and then develop mathematical or computer models afterward to show how the collected data fit with theory. In his work, Rob Phillips flips that practice on its head. The Caltech biophysicist tackles questions in cellular biology as a physicist would—by first formulating a model that can make predictions and then testing those predictions. Using this strategy, Phillips and his group have recently developed a mathematical model that accounts for the way genes compete with each other for the proteins that regulate their expression.
A paper describing the work appears in the current issue of the journal Cell. The lead authors on the paper are Robert Brewster and Franz Weinert, postdoctoral scholars in Phillips’s lab.
Posted February 28, 2014on:
UT Southwestern Medical Center researchers created new nerve cells in the brains and spinal cords of living mammals without the need for stem cell transplants to replenish lost cells.
Although the research indicates it may someday be possible to regenerate neurons from the body’s own cells to repair traumatic brain injury or spinal cord damage or to treat conditions such as Alzheimer’s disease, the researchers stressed that it is too soon to know whether the neurons created in these initial studies resulted in any functional improvements, a goal for future research.
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Operating on a child’s heart is a challenging procedure. Not only is the organ (presumably) defective, but it’s also small, complex, and delicate. So when Louisville, KY heart surgeon Erle Austin was preparing to operate on 14-month-old Roland Lian Cung Bawi’s heart, he first showed the scans of the muscle to two other surgeons, both of whom gave him “conflicting advice on how to proceed,” according to the Courier-Journal.
Then, Austin turned to the University of Louisville’s engineering school, which hooked him up with a MakerBot Replicator 2X. (From the video, it seems that the engineers had better luck with their 3D MakerBot printers than Ars ever did.) Using a computer model generated by the boy’s radiologist, the engineers fed the MakerBot with a new kind of flexible polymer “that’s similar in consistency to heart muscle,” Timothy Gornet, manager of the rapid prototyping center at U of L, told the Courier-Journal. They printed out three cross-sections of the heart, blown up to-scale, so that the surgeons could see the interior.
his 3D medical animation shows the function of white blood cells in normal immunity. It also portrays how the human immunodeficiency virus (HIV) affects the immune system and causes acquired immunodeficiency syndrome (AIDS). Common types of antiretroviral medications used to treat HIV and AIDS are also shown.
Engineers like to make things that work. And if one wants to make something work using nanoscale components—the size of proteins, antibodies, and viruses—mimicking the behavior of cells is a good place to start since cells carry an enormous amount of information in a very tiny packet. As Erik Winfree, professor of computer science, computation and neutral systems, and bioengineering, explains, “I tend to think of cells as really small robots. Biology has programmed natural cells, but now engineers are starting to think about how we can program artificial cells. We want to program something about a micron in size, finer than the dimension of a human hair, that can interact with its chemical environment and carry out the spectrum of tasks that biological things do, but according to our instructions.”
Getting tiny things to behave is, however, a daunting task. A central problem bioengineers face when working at this scale is that when biochemical circuits, such as the one Winfree has designed, are restricted to an extremely small volume, they may cease to function as expected, even though the circuit works well in a regular test tube. Smaller populations of molecules simply do not behave the same as larger populations of the same molecules, as a recent paper in Nature Chemistry demonstrates.
What does it take to regrow bone in mass quantities? Typical bone regeneration — wherein bone is taken from a patient’s hip and grafted onto damaged bone elsewhere in the body — is limited and can cause great pain just a few years after operation. In an informative talk, Molly Stevens introduces a new stem cell application that harnesses bone’s innate ability to regenerate and produces vast quantities of bone tissue painlessly.
This 3D medical animation shows the coronary vessels in the heart and the different ways they may become blocked. The symptoms of acute coronary syndrome (ACS) are depicted. The animation finishes up with common treatments for acute coronary syndrome and heart attack.
In work inspired partly by the movie “Avatar,” one monkey could control the body of another monkey using thought alone by connecting the brain of the puppet-master monkey to the spine of the other through a prosthesis, researchers say.
These findings could help lead to implants that help patients overcome paralysis, scientists added.
Paralysis due to nerve or spinal cord damage remains a challenge for current surgical techniques. Scientists are now attempting to restore movement to such patients with brain-machine interfaces that allow people to operate computers or control robotic limbs.
Scientists at Imperial College London have discovered that iron deficiency may increase stroke risk by making the blood more sticky.
The findings, published in the journal PLOS ONE, could ultimately help with stroke prevention.
Every year, 15 million people worldwide suffer a stroke. Nearly six million die and another five million are left permanently disabled. The most common type, ischaemic stroke, occurs because the blood supply to the brain is interrupted by small clots.
The Imperial team found that iron deficiency increases the stickiness of small blood cells called platelets, which initiate blood clotting when they stick together. Although a link between iron deficiency and sticky platelets was first discovered almost 40 years ago, its role has been overlooked until now.
Genetic adaptations for life at high elevations found in residents of the Tibetan plateau likely originated around 30,000 years ago in peoples related to contemporary Sherpa. These genes were passed on to more recent migrants from lower elevations via population mixing, and then amplified by natural selection in the modern Tibetan gene pool, according to a new study by scientists from the University of Chicago and Case Western Reserve University, published in Nature Communications on Feb. 10.
The transfer of beneficial mutations between human populations and selective enrichment of these genes in descendent generations represents a novel mechanism for adaptation to new environments.
High elevations are challenging for humans because of low oxygen levels, but Tibetans spend their lives above 13,000 feet with little issue. They are better suited when compared to short-term visitors from low altitude due to physiological traits such as relatively low hemoglobin concentrations at altitude. Unique to Tibetans are variants of the EGLN1 and EPAS1 genes, key genes in the oxygen homeostasis system at all altitudes. These variants were hypothesized to have evolved around 3,000 years ago, a date which conflicts with much older archaeological evidence of human settlement in Tibet.
DNA testing can predict which men face the highest risk of deadly prostate cancer, scientists say.
The team at the Institute of Cancer Research, in London, say men could soon be offered genetic screening in a similar way to breast cancer in women.
New research from psychologists at the universities of Kent and Limerick has found that music that is felt to be ‘beautiful but sad’ can help people feel better when they’re feeling blue.
The research investigated the effects of what the researchers described as Self-Identified Sad Music (SISM) on people’s moods, paying particular attention to their reasons for choosing a particular piece of music when they were experiencing sadness – and the effect it had on them.
The study identified a number of motives for sad people to select a particular piece of music they perceive as ‘sad’, but found that in some cases their goal in listening is not necessarily to enhance mood. In fact, choosing music identified as ‘beautiful’ was the only strategy that directly predicted mood enhancement, the researchers found.
For the first time, scientists have created human lungs in a lab — an exciting step forward in regenerative medicine, but an advance that likely wont help patients for many years.”Its so darn cool,” said Joan Nichols, a researcher at the University of Texas Medical Branch. “Its been science fiction and were moving into science fact.”If the lungs work — and thats a big if — they could help the more than 1,600 people awaiting a lung transplant. Lungs are one of many body parts being manufactured in the lab — some parts, such as tracheas and livers, are even further along.
Posted February 16, 2014on:
The rise and fall of empires, the march of armies, the flow of trade routes, the practice of slavery — all these events have led to a mixing of populations around the world. Such episodes have left a record in the human genome, but one that has so far been too complex to decipher on a global scale.
Now, geneticists applying new statistical approaches have taken a first shot at both identifying and dating the major population mixture events of the last 4,000 years, with the goal of providing a new source of information for historians.
Posted February 12, 2014on:
Whether human or animal, vertebrate or invertebrate, nearly every creature begins life as a tiny clump of cells. Before those cells can begin blossoming toward being a fully formed organism, however, they first must reorganize themselves into layers, each of which goes on to form complex structures such as internal organs, skin, muscle, and bone.
The signals that trigger that reorganization, however, have been largely a mystery, until now.
Scientists at Harvard have identified a previously unknown embryonic signal, dubbed Toddler, that instructs cells to move and reorganize, through a process known as gastrulation, into three layers: the ectoderm, mesoderm, and endoderm. The new signal is described in a Jan. 9 paper in the journal Science.
It is a feeling we all know – the moment when a light goes on in your head. In a sudden flash of inspiration, a new idea is born. Today, scientists are using some unusual techniques to try to work out how these moments of creativity – whether big, small or life-changing – come about. They have devised a series of puzzles and brainteasers to draw out our creative behaviour, while the very latest neuroimaging technology means researchers can actually peer inside our brains and witness the creative spark as it happens. What they are discovering could have the power to make every one of us more creative
To reduce the severity of his seizures, Joe had the bridge between his left and right cerebral hemisphers (the corpus callosum) severed. As a result, his left and right brains no longer communicate through that pathway.
Researchers have transformed specialized cells into an embryonic-like state simply by stressing them out a bit—an unexpected finding that may offer an easier route for treating diseases with patient-specific stem cells.
Stem cells that can become all other tissue types are typically obtained in two ways. One requires the destruction of an embryonic clone of a patient, which is ethically controversial. The other, which uses genes to reprogram a patient\’s mature cells into an embryonic-like state, carries the risk of cancer.
Now, in a series of pathbreaking experiments done over five years, scientists have shown that merely exposing blood cells from newborn mice to a low-acid environment—the source of stress—changes them to an embryonic-like state. The key advantage is that no potentially risky genetic manipulation was needed.
New Technique Shows Living Cells In 3-D
A new method of creating 3-D images of living cells without disturbing them promises to open an unprecedented view into how they operate.
University of Illinois engineers say the technique, called white-light diffraction tomography, will let researchers watch cellular processes as they unfold, the effects of drugs and how stem cells change into specialized cells.
The technique uses conventional microscopes and white light, so scientists don’t have to bathe bacterial or other cells in dyes, other chemicals, radiation or mechanical forces that would destroy them.
In the 1960s patients with a blocked artery would have required major open surgery and a hospital stay of a week or more.
Half a century on, patients are treated in a matter of hours and return home the same day – and it\’s all thanks to the angioplasty procedure.
Dr Duncan Ettles, president of the British Society of Interventional Radiology and a consultant vascular radiologist, says it has had a revolutionary impact on medicine.
Instead of opening up blood vessels to remove a blockage, doctors can access and treat them simply by inserting a catheter into an artery and following its movements on an X-ray screen.
Scientists from Case Western Reserve University and University of Kansas Medical Center have restored behavior—in this case, the ability to reach through a narrow opening and grasp food—using a neural prosthesis in a rat model of brain injury.
Ultimately, the team hopes to develop a device that rapidly and substantially improves function after brain injury in humans. There is no such commercial treatment for the 1.5 million Americans, including soldiers in Afghanistan and Iraq, who suffer traumatic brain injuries (TBI), or the nearly 800,000 stroke victims who suffer weakness or paralysis in the United States, annually.
The prosthesis, called a brain-machine-brain interface, is a closed-loop microelectronic system. It records signals from one part of the brain, processes them in real time, and then bridges the injury by stimulating a second part of the brain that had lost connectivity.
Their work is published online this week in the science journal Proceedings of the National Academy of Sciences.
“Beige fat” cells found in healthy subcutaneous fat in mice play a critical role in protecting the body from the disease risks of obesity, report researchers at Dana-Farber Cancer Institute, who say their study findings may have implications for therapy of obesity-related illness in humans.
A report in the journal Cell suggests that the presence of beige fat, a type of fat cell that can burn energy to release heat, is what makes subcutaneous obesity relatively healthy compared with visceral fat inside the abdomen, which largely lacks beige fat cells and is associated with increased risks of diabetes, heart disease, and death.
Excess calories in overweight people are stored in fatty tissues mainly composed of white fat cells. Beige fat is present in scattered deposits in adult humans, mixed in with white fat. Beige cells can activate a “thermogenic” mechanism that burns stored fat to make heat. When this occurs within white fat, the process is called “browning.”
Recent studies suggesting that heavier people with diabetes have lower death rates than normal weight patients may be a myth.
A strong body of research shows that being overweight or obese puts people at risk for chronic conditions like heart disease, diabetes, cancer and even early death. But several small studies connecting obesity to a protective effect against type 2 diabetes-related death have raised questions about a possible ‘obesity paradox,’ and whether weight can be a benefit in preventing progression of the disease. A 2012 study published in the journal JAMA, for example, studied 2,625 people recently diagnosed with type 2 diabetes, of which only 12% were normal weight. But the larger people with diabetes lived longer than their thinner peers.
Why the heavier people lived longer wasn’t clear; the researchers speculated that genetics, or the type of fat that certain obese people accumulated compared to normal weight individuals could be responsible.
But in a new study published in the New England Journal of Medicine, scientists say that’s unlikely. “We didn’t see this protective effect at all,” the study’s leader, Diedre Tobias of the Harvard School of Public Health, told the Associated Press. “The lowest risk was seen in the normal-weight category.”
Every year, the approach of flu season sets off a medical guessing game, with life or death consequences.
There are many different strains of flu, and they vary from year to year. So each season, health authorities must make an educated guess and tell manufacturers which variants of the flu their vaccines should target.
Even when this system works, flu-related illnesses kill 3,000 to 49,000 Americans annually, according to the Centers for Disease Control and Prevention. A bad guess or the unexpected emergence of a virulent strain can send the death toll higher than expected.
Against this backdrop, Stanford researchers report promising steps toward the creation of a universal flu vaccine, one that could be produced more quickly and offer broader protection than the virus-specific inoculants available today.
Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. The lobes and lobules are connected by thin tubes called ducts.
Anatomy of the female breast. The nipple and areola are shown on the outside of the breast. The lymph nodes, lobes, lobules, ducts, and other parts of the inside of the breast are also shown.
Each breast also contains blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. The lymph vessels lead to small, bean-shaped organs called lymph nodes that help the body fight infection and disease. Lymph nodes are found throughout the body. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.
Did viruses help make us human? As weird as it sounds, the question is actually a reasonable one to ask. And now scientists have offered some evidence that the answer may be yes.
If you’re sick right now with the flu or a cold, the viruses infecting you are just passing through. They invade your cells and make new copies of themselves, which burst forth and infect other cells. Eventually your immune system will wipe them out, but there’s a fair chance some of them may escape and infect someone else.
But sometimes viruses can merge into our genomes. Some viruses, for example, hijack our cells by inserting its genes into our own DNA. If they happen to slip into the genome of an egg, they can potentially get a new lease on life. If the egg is fertilized and grows into an embryo, the new cells will also contain the virus’s DNA. And when that embryo be
This 3d medical animation illustrates the story of how the buildup of cholesterol plaque causes a heart attack (myocardial infarction) from a blocked coronary artery due to atherosclerosis, which is chronic inflammation of the blood vessels. Beginning with damage to the endothelial arterial wall, the animation shows how a white blood cell entering the wall of the artery differentiates (changes) into a macrophage, grabbing and digesting cholesterol.
As the cell does its job, it transforms into a foam cell, which, unfortunately, becomes part of the plaque within the blood vessel wall. Ultimately, over a period of years, the plaque grows and ruptures the blood vessel wall, spilling into the blood stream and eventually blocking the left anterior descending coronary artery (LAD) supplying the left ventricle.
Posted January 14, 2014on:
Using bits of human intestine stored in a Philadelphia medical museum in 1849, scientists have decoded the genes of an early form of cholera, the deadly diarrheal disease that first swept the globe just a few decades earlier.
The disease is still a lethal menace, as was shown in Haiti four years ago, when an unexpected outbreak after an earthquake killed more than 8,000 and hospitalized hundreds of thousands more. But it has evolved since the 19th-century pandemics, which killed millions; the new work, by scientists at McMaster University in Ontario, creates the first chance to study the genome of the pandemic “classical” strain and understand its roots.
You may receive endotracheal intubation and mechanical ventilation if you are in an emergency situation involving severe respiratory problems or if you are having general anesthesia during a surgical procedure. If you have severe respiratory problems, the oxygen levels in your blood may drop too low, or the carbon dioxide levels may rise too high. Either of these conditions can result in damage to your vital organs, including your heart and brain. Under these circumstances, you may need additional oxygen or breathing support through mechanical ventilation.
We’re much better at saving the lives of those who suffer a heart attack these days. Sadly, many people survive a heart attack only to later succumb to heart failure from the damage it caused. Modern methods help heal the heart somewhat after a heart attack, but cardiologists think stem cell therapy might one day offer a far superior alternative.Stem cells aren’t just good for growing new organs, they can also heal old or damaged ones from the inside.
Thousands of patients whose hearts were damaged in a heart attack have undergone some form of stem cell therapy worldwide, and the results are promising. But there’s a problem. Once in the heart, the cells don’t tend to stay put.Dr. W. Robert Taylor, professor of medicine at Emory and Georgia Tech and director of Emory’s cardiology division, recently co-authored a paper on a new technique that may significantly increase the efficacy of stem cell therapy in the heart.
University of Toronto researchers have developed a method that can rapidly screen human stem cells and better control what they will turn into. The technology could have potential use in regenerative medicine and drug development. Findings are published in this week\’s issue of the journal Nature Methods.
“The work allows for a better understanding of how to turn stem cells into clinically useful cell types more efficiently,” according to Emanuel Nazareth, a PhD student at the Institute of Biomaterials & Biomedical Engineering (IBBME) at the University of Toronto.
Scientists at the NYU Langone Medical Center report the discovery of a novel mechanism by which Staphylococcus aureus bacteria attack and kill off immune cells. They say their findings “Staphylococcus aureus Leukotoxin ED Targets the Chemokine Receptors CXCR1 and CXCR2 to Kill Leukocytes and Promote Infection”, published today in the journal Cell Host & Microbe, explain a critical survival tactic of a pathogen that causes more skin and heart infections than any other microbe, and kills more than 100,000 Americans every year.
“The Staphylococcus aureus leukotoxin ED LukED is a pore-forming toxin required for the lethality associated with bacteremia in murine models,” wrote the researchers. “LukED targets the chemokine receptor CCR5 to kill T lymphocytes, macrophages, and dendritic cells. LukED also kills CCR5-deficient cells like neutrophils, suggesting the existence of additional cellular receptors. Here we identify the chemokine receptors CXCR1 and CXCR2 as the targets of LukED on neutrophils.”
In this compassionate video, the monaco humanitarian aid organization describes a 12 year old girl, Aminata Keita who lives in Barnako, in the African country of Mali with a heart condition. Aminata suffers from cardiomyopathy, which results in failure of the heart and requires complicated and dangerous open heart surgery. Cardiomyophathy results from the deterioration of the heart muscle (called myocardium). This in turn results in heart failure, because the heart can not pump enough blood, thus results in edema, breathlessness and irregular heart beat which can lead to sudden death. In this case Aminata’s condition was caused by a defective heart valves, which progressively causes the heart muscle to deteriorate. In order to reverse Aminata’s heart problem this defective valve has to be fixed, which would result in complete cure of her condition.
This sort of surgery is not possible in Mali and thanks to Monaco humanitarian organization, she was taken to cardio thoracic center of Monaca to perform this life-saving operation. This thoracic cardiac center is world-wide known and performs state of the art heart surgeries in children. This sort of surgery can be very costly, in the United States for example, it can cost up $100,000 ! Even if the surgery was possible to perform in Mali, clearly it would be beyond the means of most of their citizens who live below poverty levels and even the government of this country could not afford to provide. It is important to recognize the importance of these charities who provide this sort of health aid to poor nations.
Link to video: http://unr.ly/15XFdDG
A study published in the Journal of Neuroscience found that a version of a gene coding for a receptor for the brain chemical dopamine was 66% more common among people who lived to be 90 or older than among a group of younger people who were otherwise similar. The variant leads to a weaker response to the neurotransmitter, lowering the activity of the dopamine system that is responsible for generating feelings of pleasure, desire and reward, as well as for regulating movement.
Graduate student Vanessa Ridaura and colleagues at the Center for Genome Sciences and Systems Biology, University of Washington School of Medicine reported in the September 6 issue of Science that mice lacking bacterial colonies of their own that received gut bacteria from obese humans put on more weight and accumulated more fat than mice that were given bacteria from the guts of lean humans.
To directly test the influence of the human gut microbiome on obesity, the investigators sampled microbes living in the guts of human fraternal and identical twins, one of whom was lean while the other, obese. They introduced these microbes into germ-free mice fed low-fat mouse chow, as well as diets representing different levels of saturated fat and fruit and vegetable consumption typical of the U.S. diet. Increased total body and fat mass, as well as obesity-associated metabolic phenotypes, were transmissible with uncultured fecal communities and with their corresponding fecal bacterial culture collections.
Anxiety disorders, which include posttraumatic stress disorder, social phobias and obsessive-compulsive disorder, affect 40 million American adults in a given year. Currently available treatments, such as antianxiety drugs, are not always effective and have unwanted side effects.
To develop better treatments, a more specific understanding of the brain circuits that produce anxiety is necessary, says Kay Tye, an assistant professor of brain and cognitive sciences and member of MIT’s Picower Institute for Learning and Memory.
The tips of long neuronal extensions from the amygdala (green) contact neurons of the hippocampus (blue). This communication pathway helps to modulate anxiety.
IMAGE: ADA FELIX-ORTIZ
Scientists have grown miniature human brains in test tubes, creating a “tool” that will allow them to watch how the organs develop in the womb and, they hope, increase their understanding of neurological and mental problems.
Just a few millimetres across, the “cerebral organoids” are built up of layers of brain cells with defined regions that resemble those seen in immature, embryonic brains.
The scientists say the organoids will be useful for biologists who want to analyse how conditions such as schizophrenia or autism occur in the brain. Though these are usually diagnosed in older people some of the underlying defects occur during the brain’s early development.
The organoids are also expected to be useful in the development and testing of drugs. At present this is done using laboratory animals or isolated human cells; the new organoids could allow pharmacologists to test drugs in more human-like settings.
Stem cell scientists at Edinburgh and the Institute of Molecular Biotechnology in Vienna grew this organoid, or tiny ‘brain’, which measures just 4mm across. Photograph: Madeline A Lancaster/PA
Posted August 25, 2013on:
For most of the past 40 years, cancers have been treated by surgery, radiotherapy or chemotherapy. This last technique involves the use of cytotoxic drugs which can kill cells that they encounter. By carefully adjusting doses of these drugs, doctors have been able to kill off cancer cells while leaving normal cells unaffected – in many cases. But the considerable toxicity of chemotherapy drugs means they can only be administered for a few weeks, which limits their tumour-killing potential.