In the present study, the association between the activation of PAR4 and expression of p16 protein and gene, as well as the enrichments of DNMT1 and HDAC2 on the p16 promoter, was examined by Western blotting, quantitative real-time PCR (qRT-PCR), and chromatin immunoprecipitation-PCR (ChIP-PCR) methods to identify the potentially diagnostic or therapeutic value of PAR4 in ESCC. The gene discussed is HDAC2; the disease is esophageal squamous cell carcinoma.