To investigate the effect of Cox-2 inhibitors on EMT in three human bladder cancer cell lines, we examined the mRNA expressions of epithelial markers (E-cadherin and Cytokeratin), mesenchymal markers (Vimentin and N-cadherin) and EMT-transcriptional factors (SNAIL, Slug, Twist and Zeb 1) in the cell lines with or without Cox-2 inhibitors. The gene discussed is VIM; the disease is urinary bladder carcinoma.