HIF1A and Bartsocas-Papas syndrome 1: Previous studies have reported a decrease in blood perfusion [5] and an increase in hypoxia-inducible factor-1α (HIF-1α) and VEGF expression in the bladder urothelial layer of patients with IC/BPS [6,7], which suggests a chronic microvascular ischemic condition and hypoxia occurrence in the bladder mucosa [8].