CD4 and cancer: Indeed, the presence of intratumor CD4+ T cells expressing Tfh markers (including CXCL13 and PD-1high) in multiple types of carcinomas is associated with better cancer outcomes (Gu-Trantien et al., 2013; Niogret et al., 2021) and favorable responses to anti-PD-1 therapy (Magen et al., 2022, Preprint).