Abstract
Immune checkpoint therapy has started a revolution in the field of oncology. The concept that the immune system plays a critical role in antitumor responses, which has been around for decades, has finally been proven and firmly established with elegant preclinical studies and dramatic clinical responses in patients as a result of antibodies that block inhibitory T-cell pathways. However, the clinical responses being achieved are only in a subset of patients, and more work is needed to provide a better understanding of the mechanisms that elicit tumor rejection, which will enable identification of appropriate biomarkers, reveal new targets, provide data to guide combination studies, and eventually dictate a platform that allows more patients to derive clinical benefit, including cures, with immune checkpoint therapy.