ERBB2 and gastric adenocarcinoma: In an earlier study, we studied differentiated gastric adenocarcinoma and found a HER2 protein expression rate of 40.8%, of which HER2 protein 3 + accounted for 10.8%, HER2 protein 2 + accounted for 14.2%, and HER2 protein 1 + accounted for 15.8%, while the HER2 gene amplification rate was 38.8% [20].