CD274 and metastatic melanoma: Due to the lack of public clinical information on anti-PD-1/L1 immunotherapy in OC, another two published datasets, namely, IMvigor210 and GSE78220, which recorded gene expression profiles and clinical information of patients in metastatic urothelial cancer and metastatic melanoma after anti-PD-L1 checkpoint inhibition therapy and anti-PD-1 checkpoint inhibition therapy, respectively [62, 63], were selected.