By comparison the control sera had a remarkably lower frequency of PR3-ANCA: AIH 14/65 (21.5%), AIH-PBC 3/10 (30%), PBC 9/81 (11.1%), HBV 1/32 (3.1%), HCV 0/18, healthy controls 0/48. This evidence concerns the gene PRTN3 and autoimmune hepatitis.