Purity >98%. The cystic fibrosis (CF) gene encodes a cAMP-regulated chloride channel, the CF transmembrane conductance regulator (CFTR). CFTR Inhibitor-172 is a thiazolidinone that selectively blocks the CFTR channel (Ki = 300 nM) in a voltage-independent manner. It appears to directly modulate the gating of chloride at the channel and does not prevent elevation of cAMP or inhibit other pumps or channels. In mice, CFTR inhibitor-172 prevents cholera toxin-induced fluid secretion in the small intestine, when given by intraperitoneal injection. It slows cyst growth in animal models of polycystic kidney disease. As CFTR also modulates glutathione (GSH) efflux, CFTR inhibitor-172 can affect intracellular GSH concentration and reactive oxygen species balance.