CD274 and osteosarcoma: et al. developed a study on the heterogeneity and clonal evolution of osteosarcoma, which result showed that the heterogeneity between osteosarcoma (primary and metastatic) was more significant than that within osteosarcoma, and comparing to primary lesions, the metastatic lesions have stronger immunogenicity, higher cancer antigen load, higher expression level of PD-L1 and higher level of tumor infiltrating lymphocytes [16].