CCRL2 and myelodysplastic syndrome: To identify the best payload for the development of an ADC with high activity against high-risk MDS/AML, five commonly used ADC payloads (DM1, MMAE, Exatecan, SN38, PBD) were compared and pyrrolobenzodiazepine (PBD) showed the highest cytotoxicity against the erythroleukemic/ TP53-mutated TF-1 cells, which was not affected by CCRL2 expression based on the comparison of CCRL2 wild-type (WT) or knock-out (KO) cells (Supplementary Figs. 1A-B).