More toxicities with new targets may occur when trying to differentiate between normal- versus tumor-specific antigens, since, as opposed to B-cell targeting, we cannot consider as acceptable risks the long-term myeloid aplasia or T-cell aplasia that could occur, for example, with CD33- or CD123-CARs for the treatment of acute myeloblastic leukemia, and with CD5- or CD7-CARs for T-ALL and NHL. This evidence concerns the gene CD33 and acute lymphoblastic leukemia.