Immunohistochemistry study showed that four repeated PRP injections increased the expression of the urothelial cell proliferation marker Sonic hedgehog protein and cytoskeleton marker CK5, as well as the expression of adhesive proteins E-cadherin and ZO-1, in patients with IC/BPS, indicating that PRP injections can increase progenitor cell proliferative activity and facilitate barrier protein expression. The gene discussed is TJP1; the disease is Bartsocas-Papas syndrome 1.