GPX4 deficiency in T cells significantly accelerated tumor growth (Figure 1I) and mitigated the accumulation (Figure 1J) and function (Figure 1K) of CD8+ T cells accompanying decreased infiltration of total CD4+ T cells (Supplemental Figure 1K) and CD4+Foxp3+ regulatory T cells (Supplemental Figure 1L) in comparison with the control mice. The gene discussed is CD4; the disease is neoplasm.