EGFR and gastric cancer: Studies have shown that the biomarkers that can be used for early diagnosis or prognosis of gastric cancer include “human epidermal growth factor receptor 2” (HER2) [65], “Hepatocyte growth factor receptor” (HGFR) [66], “Fibroblast growth factor receptor” (FGFR2) [67], “Epidermal growth factor receptor” (EGFR) [68], “Claudin18.2” (CLDN18.2) [69], and others.