Mean titers of PR3-ANCA CIA were significantly higher in PSC (PSC 39.9CU, AIH-PSC 58.7CU) compared to other liver cohorts (p<0.0001): AIH 17.3 CU, AIH-PBC 15.6 CU, PBC 9.8 CU, HCV 4.7 CU, HBV 4.2 CU, healthy controls 2.5 CU. This evidence concerns the gene PRTN3 and primary biliary cholangitis.