BAP1 and obesity due to melanocortin 4 receptor deficiency: Risk factors include chronic biliary tract inflammation due to primary sclerosing cholangitis, choledochal cysts, chronic cholelithiasis/choledocholithiasis, hepatolithiasis, chronic viral and non-viral liver disease, infections such as HIV, Helicobacter pylori, and certain parasitic infections, obesity, medications, CF, and several other genetic conditions such as Lynch syndrome, multiple biliary papillomatosis, and BAP1 tumor predisposition syndrome [1, 13, 21, 22].