CD47 and cancer: In vitro studies have shown that the M1 (antitumor, inflammatory) macrophage’s ability to ingest tumor cells is altered in a CD47-dependent manner; the same has not been found to be true for M2 (pro-tumor, immunosuppressive) macrophages, perhaps indicating the evolution of CD47 overexpression by cancer to evade the macrophages trying to attack it[5,6].