SIRPA and neoplasm: After engagement with CD47 on tumour cells, SIRPα is activated through phosphorylation of immunoreceptor tyrosine‐based inhibition motifs (ITIM) on its cytoplasmic tail, then recruits and activates downstream Src homology 2 domain‐containing protein tyrosine phosphatase‐1 (SHP‐1) and SHP‐2, subsequently exerts suppressive effects on phagocytosis and activation of MPs.18, 19