They express high levels of transient receptor potential vanilloid 1 (TRPV1) and P2X purinoceptor 3 (P2X3) receptors, and are significantly involved in pain sensation and urgency, particularly in pathological states such as interstitial cystitis/bladder pain syndrome (IC/BPS) and overactive bladder (OAB) [23]. The gene discussed is TRPV1; the disease is Bartsocas-Papas syndrome 1.