Anytime you read a news headline that claims a new discovery “may treat all cancer” it’s time to put your skeptic’s hat on. After all, there have been so many over-hyped “discoveries” over the years that later flopped, that it would be natural to question the headline writer. And yet, this time, maybe, this one has some substance behind it.

Researchers at the University of Cardiff in Wales have discovered a new kind of immune cell, a so-called “killer T-cell”, that appears to be able to target and kill many human cancer cells, such as those found in breast, prostate and lung cancer. At least in the lab.

The immune system is our body’s defense against all sorts of threats, from colds and flu to cancer. But many cancers are able to trick the immune system and evade detection as they spread throughout the body. The researchers found one T-cell receptor (TCR) that appears to be able to identify cancer cells and target them, but leave healthy tissues alone.

In an interview with the BBC, Prof. Andrew Sewell, the lead researcher on the study said: “There’s a chance here to treat every patient. Previously nobody believed this could be possible. It raises the prospect of a ‘one-size-fits-all’ cancer treatment, a single type of T-cell that could be capable of destroying many different types of cancers across the population.”

The study, published in the journal Nature Immunology, suggests the TCR works by using a molecule called MR1 to identify cancerous cells. MR1 is found on every cell in our body but in cancerous cells it appears to give off a different signal, which enables the TCR to identify it as a threat.

When the researchers injected this TCR into mice that had cancer it was able to clear away many of the cells. The researchers admit there is still a long way to go before they know if this approach will work in people, but Sewell says they are encouraged by their early results.

“There are plenty of hurdles to overcome. However, if this testing is successful, then I would hope this new treatment could be in use in patients in a few years’ time.”

CIRM is funding a number of clinical trials that use a similar approach to targeting cancers, taking the patient’s own immune T-cells and, in the lab, “re-educating” to be able to recognize the cancerous cells. Those cells are then returned to the patient where it’s hoped they’ll identify and destroy the cancer. You can read about those here , here, here, here, and here.