CD8A and head and neck squamous cell carcinoma: To address this gap, we aimed to identify a biomarker capable of predicting immunotherapy response and serving as a therapeutic target to enhance efficacy. First, we employed four HNSCC ICI‐therapy scRNA‐seq datasets to assess CD8+ Texterm cell infiltration dynamics across treatment timepoints (pre‐ vs post‐treatment) and response groups (responders vs non‐responders).