While the original CD19 CARTs built with FMC63 mAb (KD=0.328nM) generated remarkable antitumor efficacy and have been approved by FDA, recent studies showed that CD19 CARTs made with a new mAb CAT with lower affinity (KD=14nM) generated enhanced expansion and prolonged persistence in treating refractory AML compared to the FMC63-based CD19 CART (151). Here, CD19 is linked to acute myeloid leukemia.