The fraction of CAR T-cells with sustained CD25 expression at day 6 of co-incubation was significantly higher in CAR T-cells engaging MOLM13-TP53−/− AML cells than those engaging MOLM13-TP53+/+ AML cells (Fig. 2B,C; Appendix Fig. S1). Here, TP53 is linked to acute myeloid leukemia.