Strikingly, among advanced oral cancer patients treated with PD1/PD-L1 inhibitors, MAPK pathway mutations appeared to predict a 3.3 times longer median OS versus WT (33 versus 10 mo, P = 0.0466; Fig 7E; all tumors with >10% tumor purity), supportive of a CD8+ T-cell–inflamed phenotype for improved ICI outcome. Here, CD8A is linked to lip and oral cavity carcinoma.