Immunotherapy is a form of cancer treatment that aids your immune system in the fight against cancer. In general, the immune system helps the body battle all infections and other diseases. It comprises organs and tissues of the lymph system, and white blood cells. This is a form of biological therapy as it makes use of material from living organisms to remedy cancer. Some forms of immunotherapy assist the immune system in its annihilation of cancer cells whereas some other types of immunotherapy combine with immune cells to help them in destroying cancerous cells.