TJP1 and Bartsocas-Papas syndrome 1: Compared to the control bladder tissue, the bladder tissue of IC/BPS patients had significantly decreased expression of tight junction proteins (e.g., E-cadherin, zonula occludens-1 (ZO-1)), impaired cell adhesion, alleviated cell proliferation in the basal layers, increased urothelial apoptosis, and strengthened oxidative stress protein [65,66,67].