Our study and other data confirmed the co-expression of gastrin and CCK-BR in several cancers, including gastric adenocarcinoma, hepatocellular carcinoma, lung squamous cell carcinoma, and infiltrating ductal carcinoma of the breast, and cancer cell lines by cancer tissue microarray, immunohistochemistry, and immunocytochemistry 22, 23. Here, GAST is linked to invasive ductal breast carcinoma.