In the present study by using rat model of bladder cancer induced by known urothelial carcinogen, N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), which is a downstream metabolite of N-nitrosodibutylamine, found in tobacco smoke12, we asked how bladder cancer affects DSM contractility dependent on the activation of heat-sensitive TRPs of vanilloid subfamily, TRPV1, TRPV2 and TRPV4, and large conductance (BK) member of KCa family. This evidence concerns the gene TRPV4 and urinary bladder cancer.