AREG and head and neck squamous cell carcinoma: Then, OS analysis of patients stratified by the expression levels of the 11 key genes revealed that AREG and CAV1 were associated with poor prognosis in HNSCC patients, C19orf57 and STAG3 were associated with favorable prognosis, and the other 7 genes were not significantly associated with OS (Additional file 2: Figure S2).