WDFY4, a large protein of unknown function primarily expressed in immune tissues [33], has been reported that WDFY4 is a susceptibility gene for a variety of autoimmune diseases, such as lupus erythematosus, primary biliary cholangitis, idiopathic arthritis and type 1 diabetes [19, 20, 34]. Here, WDFY4 is linked to primary biliary cholangitis.