Early efforts in epitope-editing included CRISPR/Cas9-mediated CD33 knock-out in CD33-positive tumor cells and primary HSPCs, demonstrating its feasiblility.356–358 More recent advancements, such as the work led by Casirati et al., successfully performed epitope engineering of donor CD34+ HSPCs to confer resistance to CAR-T cells targeting FLT3, CD123, and KIT antigens.359 The authors confirmed the resistance of epitope-edited hematopoiesis and the subsequent eradication of PDXs after CAR-T cell treatment. Here, CD33 is linked to neoplasm.