Immunotherapy (also called biologic therapy) is designed to boost the body’s natural defenses to fight the cancer. It uses materials made either by the body or in a laboratory to bolster, target, or restore immune system function. Recombinant interferon alpha (Alferon, Roferon-A, Intron A) is used as a treatment for ATLL. Interferon is a natural protein found in the body that stimulates the immune system. Learn more about immunotherapy.