CD4 and autoimmune hepatitis: CD4+ T cells are considered to be the key cells in the occurrence and development of AIH, and liver damage in AIH may be caused and mediated by CD4 T lymphocytes that recognize self-antigens [3].Presentation of peptides contained by HLA class II molecules by antigen-presenting cells to naive CD4 helper T cells is the initiation of pathogenesis [4–6].