High PD-L1 expression in gastric tumors, which is associated with MSI- and EBV-positive GC molecular subtypes, is considered a positive predictive biomarker for the effectiveness of PD-L1 inhibitors, while its overexpression is correlated with lymph node dissemination and metastasis, leading to dismal prognosis [85,86,87] and reduced survival [88]. The gene discussed is CD274; the disease is gastric cancer.