Immunotherapy is a new, groundbreaking approach to treating cancer that harnesses the body’s own natural defenses to fight tumors. Immunotherapy comes in many forms, including checkpoint inhibitors, which shut down a tumor’s ability to be invisible to the body’s immune system; antibodies that can stick to and attack a tumor; and genetically manipulated cells that become “natural killer cells.” Ted Teknos, MD, President and Scientific Director of UH Seidman Cancer Center, explains how these medical wonders work and which cancers immunotherapies are most effective at treating.