In a rat model for Barrett’s carcinogenesis, the IHC study demonstrated a significant overexpression of HER2 and its downstream AKT in EAC compared to a normal squamous esophagus (9.4-fold) and BE (6.0-fold), and the CLE findings after systemic injection of fluorescent-labeled anti-HER2 antibody in vivo demonstrated heterogeneous overexpression of HER2 in cancer, but with no signal in normal or NDBE tissues. Here, ERBB2 is linked to cancer.