In the aspect of mutation profiling, branched-chain amino acid (BCAA) consumption (valine/leucine/isoleucine degradation) (HSD17B10, DBT, ALDH7A1, HMGCS2, OXCT1, MCCC1, ACAT1, ALDH3A2, HADHB) [P < 0.001, fold enrichment (FE) = 5.45] was the most significant signaling pathway in the short-term PMS HNSCC only group. The gene discussed is HMGCS2; the disease is head and neck squamous cell carcinoma.