CD33 and acute myeloid leukemia: The dramatic enhancement of UCART33 expansion, persistence, and anti-tumor efficacy against CD33+ AML targets in vivo by rhIL-7-hyFc recapitulate our data generated using UCART19, suggesting that rhIL-7-hyFc potentiation of UCART expansion and clinical efficacy is likely applicable to multiple other CAR T platforms and targets.