<prompt> Interferon gamma is used for treatment of -HBVHCVOsteopetrosisBoth HBV and HCV  <response>: Ans. is c i.e., Osteopetrosis o Interferon alfa-2b and alfa-2a are used in -- chronic hepatitis B and C, and in some malignancies. o Interferon beta-la is used in multiple sclerosis. o Interferon gamma-lb is used in chronic granulomatous disease and osteopetrosis. 