An important part of the immune system are proteins called antibodies. The immune system makes antibodies to attach to the antigens which are usually found on the surface of cells. The antigens can then be identified and destroyed by antibodies or other cells in the immune system.
Antibodies hold promise in the treatment of cancer.
They then alert other cells in the immune system to the presence of the cancer cells. MABs are classified as Biological Response Modifiers. Since they affect the immune system they are called immunotherapy as opposed to chemotherapy which are drugs which tend to interfere in cancer cell growth. Researchers make MABs by injecting human cancer cells into mice so that their immune systems will make antibodies against these cancer cells. Hybridomas are like factories that can indefinitely produce large quantities of these pure monoclonal antibodies.