Despite a loss of E-cadherin protein expression in both HNSCC lines FaDu and Kyse30 following EGF treatment, E-cadherin mRNA levels remained unaffected in Kyse30 cells, suggesting additional posttranslational effects of EGF/EGFR/ERK1/2 on E-cadherin expression. This evidence concerns the gene MAPK3 and head and neck squamous cell carcinoma.