TP53 and head and neck squamous cell carcinoma: We also explored the relationship between NT5E and methylation level, and the results showed that compared with normal tissues, NT5E had a higher degree of methylation in HNSCC (Figure 2(e), P < 0.05), which was more reflected in TP53 nonmutant HNSCC (Figure 2(f), P < 0.05).