CD274 and synovial sarcoma: Other authors reported increased expression of PD-L1 with densities of CD8+ cells in gastric and gastroesophageal junction tumors, hepatocellular carcinoma,15 and synovial sarcoma.16 In NSCLC, the expression of PD-L1 and CD8+ cells was studied by different investigators to evaluate the correlation between them and their predictive values.