The expression level of TREM2 is significantly upregulated in tumor tissues of patients with gastric cancer (GC) (47), oral squamous cell carcinoma (OSCC) (48), lung cancer (49), papillary thyroid carcinoma (PTC) (50), renal cell carcinoma (RCC) (51), and prostate cancer (PRAD) (52). This evidence concerns the gene TREM2 and gastric cancer.