In addition, gastric adenocarcinoma patients with POLE/POLD1 mutations usually show adaptive immune resistance to the tumor microenvironment, loss of mismatch repair protein, increased PD-L1 expression, and higher TMB, suggesting that the POLE/POLD1 mutation could be used as a biomarker to improve the clinical efficiency of precision medicine in gastric adenocarcinoma patients [61]. This evidence concerns the gene POLD1 and gastric adenocarcinoma.