SIRPA and neoplasm: Conversely, in CD38/CD47 double-positive Reh cells, our BsAbs had a 200- to 500-fold greater inhibitory effect on the CD47/SIRPα interaction than the same monospecific CD47 ligand trap molecule, indicating that the inhibition of CD47/SIRPα by our BsAbs is dependent on the engagement of CD38 on tumor cells.