The amplification of GPC2 accounted for the largest proportion of all mutation types, of which esophageal squamous cell carcinoma, esophagogastric adenocarcinoma, and CHOL had the highest occurrence rates of 8.42%, 6.42%, and 5.56%, respectively (Figure 11). This evidence concerns the gene GPC2 and gastroesophageal junction adenocarcinoma.