Fluoropyrimidine plus platinum-based systemic therapy is a standard first-line regimen for unresectable advanced or metastatic human epidermal growth factor receptor 2 (HER2)- negative gastric and GEJ adenocarcinoma and should be part of the standard backbone in the limited metastatic disease [59,60,61,62,63,64,65]. Here, ERBB2 is linked to gastroesophageal junction adenocarcinoma.