TRPV4 and Bartsocas-Papas syndrome 1: In the correlation analysis among all IC/BPs patients and controls, TRPV1 negatively associated with bladder volume (r = −0.294) and bladder compliance (r = −0.313), TRPV4 positively associated with voiding detrusor pressure (r = 0.278), and P2X3 negatively associated with the first sensation of bladder filling (r = −0.261).