Tasmanian devils are notoriously nasty, even to each other. They have teeth and aren’t afraid to use them. As a result, they tend to bite and nip at the faces of their brethren. And unfortunately, this has resulted in the spread of a contagious form of cancer that has wiped out 70% of the population.
But there is good news. Researchers have discovered that the reason the tumors are able to spread so efficiently (escaping immune system detection) is that its cells lack major histocompatibility complex molecules, or MHC molecules. The Tasmanian devil’s immune system can’t ‘see’ what’s coming. This, of course, isn’t unique amongst cancer cells, but what is a little different is that these MHC molecules aren’t simply broken via mutation. They are actually turned off due to regulation. This means they are intact and can be turned back on. (It also means that, in conjunction with the contagious factor, it wouldn’t be inappropriate to consider this cancer a separate organism, however parasitic.)
There is hope for the Tasmanian devil, albeit far down the road. Until then, quarantine and luck are the only viable solutions for saving this animal from extinction.