CTLA4 and autoimmune hepatitis: We analyzed a large panel of intra-hepatic ICM (PD-1, TIM3, LAG3, CTLA-4, OX40, 4-1BB) expressed by different immune cells, and demonstrated that untreated AIH patients are characterized by a high frequency of activated intrahepatic T cells expressing PD-1 and 4-1BB, Figure 4.