CNR1 and chronic cystitis: With respect to our primary study substance BCP, Gertsch et al. (2008) [26] demonstrated that BCP and its isomers do not show significant binding affinity for human CB1R. In addition to Tambaro et al. (2014), and to our knowledge, there have only been a few studies that have examined the involvement of the CB2R activation in experimental cystitis [35,36].