Tasmanian Devil Tumor Disease

Recent research done at the University of Tasmania has shown that a facial tumor found in Tasmanian Devils since the 1990's is transmissible. There have been several tumor found in other animals that are as well, such as Equine Sarcoids and TVT (Transmissible Veneral Tumors) in dogs . The odd thing in this one is that the tumor has 13 chromosome pairs whereas the Devil has 14.
The jounal Nature reports that the population of devils on Tasmania has dropped from 140,000 to 80,000 since it was first discovered over 10 years ago. DFTDA (devil facial tumor disease) is thought to be spread by the biting activity of devils which pick up tumor cells on the teeth and transplant them into the next devil they bite. This suggests several things about this tumor, one , that it is fairly hearty and two, that it can bypass the bodies initial immune response to the bite wound. Normally there is a large number of white cells and components of an immune cascade that swarm to an infected area to clean up the mess,why do these cells survive? Nature postulates that it is related to the fairly homogeneous genetic make up of the devils that limits the adaptation of other species, perhaps, but it doesn't explain the lack of effectiveness of the common defense mechanisms. It will be interesting to track this one and see what the body can do in this case. I suspect that there will be an immune adaptation of simply the population will decrease to a point where bite transmission is less likely.