TFF2 and interstitial cystitis: Smet et al. (1997) found an increased distribution of specific nerve fibers containing CGRP and SP in the urinary bladder of patients with detrusor instability, and Tamaki et al. (2004) reported that subjects with interstitial cystitis may present overexpression of VEGFA in the urinary bladder. On the other hand, though the animals exposed to retinyl acetate in our study manifested a significant impairment of the urothelium barrier function, Liu et al. (2012) did not detect such an anomaly in patients with OAB.