An immune response to intrahepatic BECs through 2-OADC-specific CD4+ helper T cells and CD8+ cytotoxic T cells is thought to be the major mechanism responsible for the immunological destruction of BECs in PBC and these T cells show molecular mimicry between human and bacterial PDC-E2 [24, 25]. The gene discussed is CD4; the disease is primary biliary cholangitis.