CD4 and neoplasm: While all mice treated with vehicle-only control (HBSS) showed progressive tumors and died by Day 41, mice receiving CAR-T cells (5 out of 6 mice) or CD4+ CAR-T (5 out of 6 mice) exhibited tumor clearance (Figure 2B, C). Despite similar tumor regression kinetics and survival benefits, the persistence of CAR-T cells was superior to CD4+ CAR-T cells in the peripheral blood on day 44 following adoptive transfer (Supplementary Figure 3B, left panel).