The immune system contains a number of cell types, such as [[NK cells]] and [[cytotoxic T cell|killer T cells]] that have the capability to destroy other cells that have become infected with viruses or have become cancerous. [[Immunotherapy]] involves the enhancement or potentiation of these natural defenses against tumor cells. A common procedure is to remove immature immune cells from the patient's [[bone marrow]], purify the T-cells and expose them to [[antigen]]s from the tumor. The activated cells are then re-injected, allowing them to seek out cancerous tissues. | The immune system contains a number of cell types, such as [[NK cells]] and [[cytotoxic T cell|killer T cells]] that have the capability to destroy other cells that have become infected with viruses or have become cancerous. [[Immunotherapy]] involves the enhancement or potentiation of these natural defenses against tumor cells. A common procedure is to remove immature immune cells from the patient's [[bone marrow]], purify the T-cells and expose them to [[antigen]]s from the tumor. The activated cells are then re-injected, allowing them to seek out cancerous tissues. |