IL2 and neoplasm: The following evidence from CAR-T cell therapy19 and preclinical studies suggesting that CD4+ CAR-T cells, upon tumor recognition, produce IL-2 that augments CD8+ CAR-T cell proliferation, survival, and antitumor lytic activity43, we also generated 70% CD8+/30% CD4+ mixture of DN4.99 TCR-T cells that was effective in vivo.