HPRT1 and head and neck squamous cell carcinoma: The LASSO regression analysis identified six optimal DEMEs including ASNS, CYP27B1, TXNRD1, PLOD2, FUT6, and HPRT1. The risk score for each patient was computed as follows: risk score = (0.308) *ASNS + (0.228) * CYP27B1 + (0.284) * TXNRD1 + (0.174) * PLOD2 + (-0.092) * FUT6 + (0.362) * HPRT1. Subsequently, the HNSCC patients were divided into high- and low-risk groups based on the median value of risk scores (Figure 3A).