Blockade of the CD47-SIRPα pathway using anti-CD47 antibodies, SIRPαFc or by CD47 siRNA knockdown have been shown to increase phagocytosis of tumor cells by in vitro generated M1 and M2 macrophages [19], which represent two extremes along a continuum of macrophage activation. The gene discussed is CD47; the disease is neoplasm.