In contrast to dMMR/MSI-H GC, the expressions of tumor cell-intrinsic cGAS–STING, IFN-stimulated genes, and STING downstream T-cell attracting chemokines were significantly lower in pMMR/MSS/EBV (−) GC (Figs. 1 and 2), suggesting that the activation of the tumor cell-intrinsic cGAS–STING is maintained at a low level in pMMR/MSS/EBV (−) GC. Here, IFNA1 is linked to gastric cancer.