dMMR/MSI-H GC is characterized by high tumor mutational burden, neoantigen load, dense infiltration of immune cells such as CD8+ T cells, and higher expression of programmed cell death ligand 1 (PD-L1) compared to MMR proficient (pMMR)/microsatellite stable (MSS)/EBV (−) GC. Here, CD274 is linked to neoplasm.