Interestingly, not just CD8+ T cells but also CD4+ T cells were GrzB+, a feature reported earlier in the context of cancer,62 and the role of CD4+ T cells in antitumor immunity receives increasing attention.29 63 The frequency of cytotoxic CD4+ and CD8+ T cells in BRAFi-treated tumors was reduced on development of resistance. This evidence concerns the gene CD8A and cancer.