Fascinating and important article on finding a second "don't eat me signal" that certain cancers use to protect themselves. Article about Irving Weissman and his team's work at Stanford can be read here.
"... aggressive cancers express a ‘don’t eat me’ signal in the form of CD47 on their surfaces. Now we’ve identified a second ‘don’t eat me’ signal and its complementary receptor on macrophages. We’ve also shown that we can overcome this signal with specific antibodies and restore the ability of macrophages to kill the cancer cells.”
Irving Weissman, Stanford University School of Medicine