SIRPA and cancer: Notably, SIRPα-KO macrophages were found to promote T-cell recruitment in cancers via a Syk–Btk-dependent mechanism involving CCL8 secretion, transforming tumor-associated macrophages and granulocytic myeloid-derived suppressor cells into subsets expressing high levels of CCL8 and H2-Q10, respectively, with enhanced antigen presentation, phagocytosis, inflammatory response, and chemotaxis capacities (36).