They found more TCF7+CD8+ cells in responding samples, whereas more TCF7−CD8+ cells were in non-responding samples, which suggests the ratio of CD8+TCF7+ to CD8+TCF7− tumor-infiltrating lymphocytes is strongly correlated with improved response and survival in melanoma patients treated with anti-PD-1 [34,39]. This evidence concerns the gene TCF7 and melanoma.