The strengths of this study include its comprehensive approach, which encompasses a large cohort of patients with gastric or GEJ adenocarcinoma over a nearly five‐year period, rigorous histopathological and molecular analyses using HER‐2 and MSI markers, and a detailed examination of clinicopathological characteristics and survival outcomes. This evidence concerns the gene ERBB2 and gastroesophageal junction adenocarcinoma.