The specific utility of checkpoint blockade against these tumors was suggested by two key findings: 1) the classic side effect of hypophysitis in patients treated with immune checkpoint blockade for other cancers (implying the capacity for these therapies to elicit a T cell response in the gland) [3]; and 2) the discovery of increased levels of PD-L1 on the surface of functioning adenomas [4]. Here, CD274 is linked to cancer.