ARE-Del-/- mice with chronic low expression of IFNγ are generated by genetic deletion of the AU-rich element (ARE) in the 3’-UTR region of IFNG. Given that PBC is thought to be a Th1-mediated autoimmune disease, our findings support a primary role for IFNγ in the development of PBC. The gene discussed is IFNG; the disease is autoimmune disease.