CD274 and cancer: Upregulation of PD-L1 in a series of human cancers, including non-small cell lung cancer (NSCLC), melanoma and gastric cancer, results in T cell inactivation and escape of these cancers from immune surveillance.2 Therefore, therapeutic blockade of PD-L1 is rapidly becoming a therapeutic option for the treatment of cancers that exhibit overexpression of PD-L1.