IFNG and Alzheimer disease: The main treatment option of moderate (15 ≤ SCORAD < 40) to severe AD (SCORAD ≥ 40) includes systemic immunosuppressants, such as steroids, cyclosporine, azathioprine, methotrexate, interferon-gamma (INF-γ), intravenous immunoglobulin, allergen-specific immunotherapy and phototherapy.