CD8A and head and neck squamous cell carcinoma: Our in-house MAPK pathway-mutated HNSCC tumors also demonstrated increases in CD8+ T-cells (accompanied by dendritic cells and neutrophil infiltrations) by immunohistochemistry, consistent with the TIMER-predicted CD8+ T-cell–inflamed, immunoactive microenvironments borne by MAPK-mutated HNSCC tumors in TCGA (Figs 5C and S10).