Biological therapy consists of using a living organism substance derived either from living organisms or laboratory produced variations of the substances to treat a particular disease. Biological therapies generally comprise interleukins, interferons, monoclonal antibodies, vaccines and so on. Biological therapy utilizes the bodys immune system either directly or indirectly in order to fight cancer. Some biological therapies for cancer use vaccines or bacteria to stimulate the bodys immune system to act against cancer cells where as some therapies involve antibodies.