We show that both polyfunctional CD4+ effector cells, which arose in vivo from infused naïve T cells, and in vitro-generated Th1 cells, expressed IL-7Rα (Figs 1B and 5B) and responded to exogenous IL-7 (Figs 4 and 5), while donor CD4+ T cells tolerized in unconditioned tumor-bearing mice failed to regain IL-7Rα expression (Fig. 1A) and were unresponsive to rhIL-7 (Fig. 4A). Here, CD4 is linked to neoplasm.