EZH2 and head and neck squamous cell carcinoma: The EZH2 mRNA expression was higher in both Hep2 and HK1 cells (P<0.01), and the SIDT1 mRNA expression was lower in both Hep2 and HK1 cells (P<0.01); these results are consistent with the protein expression patterns detected in HNSCC tissues in HPA database.