Assays for angiotensin-converting enzyme [ACE] and antineutrophilic cytoplasmic antibody (ANCA) have been persistently negative, while anti-smooth–muscle autoantibody, known to be associated with autoimmune hepatitis, was found to be mildly positive (1:40, while the control values are less than 1:20). Here, ACE is linked to autoimmune hepatitis.