PPIG and chronic cystitis: Absence of ZO-1 (Slobodov et al., 2004) and increased urothelial permeability (Graham and Chai, 2006) have been reported in patients with haemorrhagic cystitis and also in animal models of CYP-induced cystitis or intravesical instillation of acrolein (Martins et al., 2012).