SIRPA and neoplasm: As canonical Wnt/β-catenin signaling plays an important role in modulating proliferation and survival of tumor cells, particularly the leukemia cells6, 7, 8, 9, we speculate that SIRPα may promote acute promyelocytic leukemia (APL) cell apoptosis and suppress APL cell survival via inhibiting Wnt/β-catenin signal pathway.