Taking HER2 expression (IHC 1+, 2+, 3+) of gastric adenocarcinoma mixed type (Lauren classification) patients as the research object, we conducted a preliminary clinical study of accurate subtyping (grouping) based on Lauren classification and referring to the intestinal and non-intestinal phenotypic characteristics in the mixed type according to the WHO classification. Here, ERBB2 is linked to gastric adenocarcinoma.