PPIG and chronic cystitis: An increase in NGF was found in chronic CYP‐induced cystitis in mice (Boudes et al. 2011) and in PBS patients (Ochodnický et al. 2011), triggering inflammatory response and sensitization of nociceptive fibers, and these effects were mediated in part by mast cells (Levi‐Montalcini et al. 1996; Ochodnický et al. 2011).