The expression of functional CB1 and CB2 receptors has been demonstrated in normal human [61,62], rat, and mouse bladder urothelium [62], as well as in the normal human urothelial cell lines HCV29 and UROtsa [63] and the transformed RT4 cell line [64], whereas no reports to date exist regarding the expression of CBD-related receptors in normal urothelial cells SV-HUC1, which are often used as an in vitro model of IC/BPS [35,41,42,43]. This evidence concerns the gene CNR1 and Bartsocas-Papas syndrome 1.