Primary sclerosing cholangitis (PSC) is an uncommon chronic liver disease characterized by progressive inflammation and destruction of the bile ducts. The disease progresses slowly, usually leading to biliary cirrhosis, portal hypertension and liver failure over a 10-15 year period. PSC is a common cause of adult cholestatic liver diseases and a primary source behind many of the liver transplantations in U.S. adults. At least 70% of PSC cases are associated with chronic inflammatory bowel disease (IBD), usually ulcerative colitis. Currently, there is no cure for PSC and prospective treatments remain ineffective.