It's totally meta!

If you live in Australia or like to keep up with biology news, you've probably heard of Tasmanian devils being driven to near-extinction - and for once it's not humans' fault! It's a thrilling tale of bad behavior, gruesome disfigurement and survival of the luckiest.

If you've gone to vet school you might also have heard of a certain canine "social" disease which defies normal epidemiology, lacking any non-canine infectious agent. What do the two have in common?

There's a certain class of disease almost certain to develop in any individual who lives long enough, by a simple accumulation of DNA errors as our cells divide. Being so similar to its host it proves devilishly hard to treat, it tends to grow systemic if untreated and if it reaches that stage it's most often fatal despite the best efforts of modern medicine. The best thing that can be said about cancer is that it's not contagious.
Usually.
Mostly.

While it may be old news to the experts, here's a dose of nightmare fuel for the rest of us: there is such a thing as infectious cancer. Even if the phenomenon hasn't appeared in humans just yet, Tasmanian devils seem to be the third documented mammalian case, so given the universe runs on Murphy's Law, let's take bets:
Will we develop our own human-derived transmissible tumors or will our species manage to somehow pick up some other mammal's cancer as a zoonosis? Wouldn't you like to be able to claim honestly to have a little devil inside you?

Either way, look at that face.
Sweet dreams.