SIRPA and neoplasm: Though the mechanism of the anti-CD47 antibody is not yet clear, the possible pathways are as follows: preventing the combination of CD47 on tumor cells and SIRPα on macrophages to activate phagocytosis, promoting the cytotoxic effect of antibody dependence and complement dependence based on Fc, directly inducing apoptosis to tumor cells, or stimulating the phagocytosis of dendritic cells to tumor cells.