PTPN11 and neoplasm: The interaction between CD47 on tumor cell surfaces and the signal-regulatory protein α (Sirp α) on TAMs triggered the activation of Src homology 2 (SH2) domain-containing tyrosine phosphatase 2 (SHP-2), initiating a “don’t eat me” signal to evade macrophage phagocytosis [197,198,199].