CD274 and gastric cancer: In particular, PD-L1 is expressed on the surface of neoplastic cells in 15–70% of GC [37], with increased expression being associated with non-metastatic cancer tissue [44], well differentiated tumors [44] and improved OS (median OS not reached vs. 40 months; p = 0.008) [45] although its association with a favorable OS has not always been consistent [37,46].