The microsatellite instability (MSI) and Epstein–Barr virus (EBV) positive subtypes are characterized by high programmed cell death ligand 1 (PD-L1) expression, a cytotoxic lymphocyte infiltrate rich in CD8+ TILs, and a high mutational rate (tumor mutational burden ≥10); these molecular classes of GC have been referred to as ‘hot tumors’ that are susceptible to immunotherapeutic drugs. The gene discussed is CD274; the disease is neoplasm.