Actimmune: Interferon gamma-1b: Manufacturer's information about this protein agent approved by the US FDA for the treatment of chronic granulomatous disease, and severe, malignant osteopetrosis.MedlinePlus: Interferon Gamma-1b (Injection): Features information about dosage, usage, warnings, and side effects.MedlinePlus: Interferon, Gamma (Systemic): Features information about dosage, usage, warnings, and side effects.