Although the etiology of AIH is not fully understood, emerging evidence indicates that proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interferon-γ (IFN-γ), and interleukin-17 (IL-17), are known mediators regulating inflammatory dysregulation in AIH (5–9). The gene discussed is IFNG; the disease is autoimmune hepatitis.