Help! Male Hormones Dampen CD4+ T-cell Help in Cancer.

Sex differences in antitumor immunity contribute to disparities in cancer outcomes, yet the role of CD4+ T helper cells in this context remains poorly understood. In this issue, Hunt and colleagues show that sex hormones restrain CD4+ T-cell help in males, weakening antitumor immune responses and promoting tumor progression. This work identifies CD4+ T-cell help as a previously underappreciated driver of sex-biased cancer immunity, with potential implications for sex-informed immunotherapy strategies. See related article by Hunt et al., p. 1068.