CD274 and non-small cell lung carcinoma: While expression of PD-L1 on tumor cells is a predictive biomarker of response to ICIs in other cancer types (i.e., NSCLC and urothelial cancers), its expression in EOC is not very frequent (10–33%) [71,72] suggesting that not all tumors rely on this pathway for immune evasion and its prognostic role in EOC is still controverted.