CD24 and cancer: The inhibitory receptor Siglec-10 on the macrophage surface binds to its ligand CD24 on cancer cells, resulting in the interaction of an ITIM or ITIM-like motif in the cytoplasmic domain of Siglec-10 with Src family kinases.198 Then, Src family kinases phosphorylate the ITIM tyrosine in the cytoplasm, thereby recruiting protein tyrosine phosphatases (PPPs), such as SHP-1 and SHP-2.199 SHP-1 specifically binds to the intracellular phosphorylated ITIM domain to dephosphorylate it, leading to cytoskeletal remodeling and phagocytosis inhibition (Fig. 5d).