From Magic Bullets to Super T Cells: Immunotherapy encompasses multiple approaches, including harnessing or enhancing immune cells, hormones, and other weapons of the immune system to destroy tumor cells, as well as releasing the brakes on the immune response that tumors trigger. This new article takes the reader on a journey from the origins of using toxins to prime the body’s immune system to attack tumors through today’s advances that genetically alter immune cells to fight cancer.