We selected nine proteins—NOSTRIN, GREM1, BAG2, OLFM4, TRIP6, IGFBP7, P3H3, LIPF, and MAGE-A9 based on their differential expression in the diffuse and intestinal subtypes and because they had not been studied in the diffuse and intestinal subtypes of gastric cancer. Here, GREM1 is linked to gastric cancer.