While CLDN18.2’s expression in gastric and gastroesophageal cancer is widely correlated with clinical, immunohistopathological, and molecular features of tumor cells like HER2, MSI, PDL-1,2, EBV [49,50,51,52], there are few articles associating its expression with tumor microenvironment markers. The gene discussed is ERBB2; the disease is neoplasm.