PTGS2 and urinary bladder carcinoma: Bladder carcinoma lesions in mice from Group 3 (n = 10; 18wks BBN) had significantly higher Cox-2 expression when compared to normal urothelium in mice from Group 1 (n = 7; control) and bladder inflammation and hyperplasia in mice from Group 2 – 12wks BBN (n = 9; 12wks BBN).