Although we did not observe a significant elimination of hematopoietic stem cells in vitro, CAR T-cells targeting CD33 could exacerbate anemia and thrombocytopenia in virtue of CD33 expression on these hematopoietic progenitors, as previously observed in preclinical models in vitro [6–8], or in vivo [9]. This evidence concerns the gene CD33 and anemia (phenotype).