Biotherapy is a kind of therapy that uses the body’s own defenses to stimulate the immune system and fight disease. Also called as biological therapy or immunotherapy, biotherapy uses certain agents to modulate the immune system so that they can provide therapeutic benefit. With the use of biological response modulators, which modify the host’s response to certain disease cells (tumor cells), disease conditions can be treated. Biotherapy is used in treatments of cancer, hepatitis C, rheumatoid arthritis, and many other diseases. The efficacy of biotherapy for type 1 diabetes is being researched.