A drug used to treat AIDS-related Kaposi sarcoma in certain patients, hairy cell leukemia, and melanoma that has been removed by surgery. It is also used with other anticancer drugs to treat a certain type of non-Hodgkin lymphoma. Interferon alfa-2b is also used to treat some infections caused by viruses, such as the hepatitis C virus. It is being studied in the treatment of other types of cancer and other conditions. Interferon alfa-2b is a form of interferon alfa (a substance normally made by cells in the immune system) and is made in the laboratory. It is a type of cytokine and a type of biological response modifier. Also called IFN alpha-2B, Intron A, and recombinant interferon alfa-2b.