PTGS2 and head and neck squamous cell carcinoma: We conducted the present study to determine whether selective Cox-2 inhibitors restore the expression of E-cadherin through the downregulation of its transcriptional repressors to suppress the EMT in HNSCC cells, and to determine whether the gene expression levels of the molecules that are implicated in the EMT are correlated with clinicopathological parameters in HNSCC.