SIRPA and neoplasm: CD47 is a transmembrane‐bound protein expressed by all normal cells throughout the body, particularly overexpressed by young red blood cells and multiple tumor cells.[198, 199, 200] Engagement of CD47 with SIRPα initiates the phosphorylation of two tyrosine residues of SIRPα cytoplasmic ITIM, leading to subsequent recruitment and activation of SH2‐domain‐containing phosphatase1 (SHP1) and 2 (SHP2).