PTPN11 and neoplasm: The binding of tumor cell CD47 to macrophage SIRP-α leads to the activation and phosphorylation of the SIRP-α ITIM motif, and recruitment of SHP-1 and SHP-2 phosphatases, which inhibit tumor cell phagocytosis by preventing the accumulation of myosin IIA at phagocytic synapses [108].