Biological therapy involves using medications or substances made by the body to increase or restore your body's natural defenses against cancer. It is also called immunotherapy. Monoclonal antibodies, cancer vaccines, and interferon are examples of biological therapy used to treat some types of lymphoma. There have recently been several new immunotherapeutic agents approved by the FDA, and this represents an area of intense research interest. Many of these are still in the development stage. If you are interested in knowing whether you are an appropriate patient to participate in such clinical trials, ask your doctor.