In our previous study, by using the chemical xenobiotic 2-octynoic acid (2-OA) coupled to the OVA (2-OA-OVA)-induced PBC mouse model, we demonstrated that the overexpression of IFN-γ enhanced liver inflammation and caused the onset of disease by increasing immune cell infiltrates, upregulating MHC class II expression of antigen-presenting cells (APCs), promoting anti-PDC-E2 antibody production, and activating CD4+ and CD8+ T and NK cells. The gene discussed is CD4; the disease is primary biliary cholangitis.