CD4 and autoimmune hepatitis: The histological hallmark of AIH is periportal or periseptal interface hepatitis, which is characterized by infiltration of macrophages, plasma cells, and lymphocytes.[9, 10, 11] T cells play a predominant role in the immune pathogenesis of AIH.[12] Emerging research indicates that in addition to CD4+ T cells, CD8+ T cells also can play an important role in the disease progression of AIH.[13, 14, 15] However, a comprehensive understanding of the role of CD8+ T cells in the pathogenesis of AIH is currently lacking.