CD274 and osteosarcoma: The lowest level of PD-L1 expression was detected in GCT (0.43 ± 0.07) compared to osteosarcoma tumors (0.91 ± 0.07) (P < 0.0001) and Ewing sarcoma (0.74 ± 0.07) (P = 0.0017) tumors; while the difference between osteosarcoma and Ewing sarcoma tumors was not statistically significant (P = 0.09).