CD274 and gastric cancer: Results from a KEYNOTE-061 trial (NCT02370498) examining the usefulness of pembrolizumab as a second-line treatment for advanced gastric cancer reported that the effect of pembrolizumab may be predicted by the combined positive score, the number of PD-L1 positive cells among tumor cells, lymphocytes, and macrophages divided by the total number of tumor cells multiplied by 100 [38].