TTI-621 (SIRPαFc) is a soluble recombinant fusion protein developed by linking the N-terminal CD47-binding domain of SIRPα with the Fc domain of IgG1 that is being studied for patients with several R/R hematologic malignancies, including AML, as part of phase 1 trial NCT02663518 (Table 1). This evidence concerns the gene CD47 and acute myeloid leukemia.