As techniques have been refined, interest in personalized mouse models of disease has risen, writes Andrew Pollack at The New York Times. While the use of such avatars has not been proven to affect patient outcomes and is expensive, Pollack says that some cancer patients are still trying that approach to learn more about how their cancers, implanted into mice, react to different drugs. One such patient, Nir Toib, tells Pollack that the combination of drugs recommended by his mouse avatar results helped treat his lung cancer while those suggested by genetic testing of his tumor did not. "I had 10 tumors on my right kidney," Toib says. "All of them disappeared."