Can immune function be therapeutically restored or enhanced?

Scientists and clinicians are now exploring the possibility of harnessing the immune system to combat cancer, among other diseases. Cancer has always proven difficult to treat because of how intertwined and similar cancer cells and healthy host cells are, and treatment options have been forced to toe the thin line between insufficiently potent (leading to disease relapse) and excessively cytotoxic (resulting in collateral damage to healthy tissue and patient quality of life). The immune system presents researchers with many examples of natural mechanisms for the selective and potent elimination of cancer cells. Understanding, utilizing, and augmenting these mechanisms for therapeutic purposes has created a new field termed “immunotherapy.”