"The bump on the back of the mouse is the size of a Tic Tac breath mint, or, possibly, a small pea.
"But for Matt Freedman, a New York artist grappling with a rare and deadly neck cancer, the tiny tumor — his tumor — represents a last-ditch hope for a healthy future.
"Freedman, 57, who was diagnosed with adenoid cystic carcinoma in 2012, is among a small but growing group of cancer patients turning to a kind of very personalized medicine in which animals serve as stand-ins to treat human disease.
"Called mouse avatars in some circles — like the virtual characters in online games — the critters are implanted with pieces of tumor harvested from their human counterparts. They’re then propagated to create a colony of animals in which to test drugs and other treatments that would be too aggressive — or take too long — to attempt in a person."