CD274 and lung cancer: The role of the Hippo pathway in upregulating PD-L1 was further confirmed in breast and lung cancer cells as mammalian STE20-like kinase 1 and 2 (MST1/2) and large tumor suppressor 1 and 2 (LATS1/2), upstream kinases and inhibitors of canonical Hippo pathway are shown to suppress PD-L1 expression (306).