SIRPA and non-small cell lung carcinoma: CD47 is overexpressed in a host of hematological malignancies, and its interaction with SIRPα on phagocytes prevents phagocytosis of tumor cells and promotes tumor evasion of immune surveillance.209,252 CD47 is expressed highly in both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).