CD4 and autoimmune hepatitis: While the strong association with distinct HLA-DRB1 alleles strongly supports an important role for CD4+ cells in disease development, the characteristic and specific elevation of immunoglobulin G (IgG) levels and the development of both specific and non-specific autoantibodies, which is also of important diagnostic value, support the role of B cells in AIH pathogenesis [1, 3–5].