IL17A and chronic cystitis: Immunohistochemical staining analysis showed that global IL-17A expression was significantly elevated in tissue sections from bladder polyp and bladder cancer compared with cystitis (Fig. 1a and b, p = 0.001 and p = 0.001, respectively), while there was no significant difference in global IL-17A immunoreactivity between bladder polyp and bladder cancer (p = 0.170).