CD47 and neoplasm: LM8 and KRIB tumor cells were labeled with carboxy fluorescein diacetate succinimidyl ester (CFSE) and co-cultured with the macrophages from NOD/SCID/IL2γnull NSG mice, which harbor a SIRPα polymorphism that results in enhanced SIRPα binding to human CD47 ligand (18, 19).