EPHX3 and head and neck squamous cell carcinoma: Previous studies have suggested that the methylation of EPHX3 (epoxide hydrolase 3), a metabolic enzyme that converted mutagenic epoxides into trans-dihydrodiols for detoxication, was considered as a predictive factor for the recurrence of prostate cancer, but as a favorable prognostic factor for HNSCC(Cottrell et al., 2007; Stott-Miller et al., 2014; Bai et al., 2019).