As Table 1 shows, pathologists usually use a semi-quantitative assessment method to assign HER2 scores for gastric cancer by repeatedly comparing hematoxylin and eosin (H&E) whole slide images (WSIs) with their HER2 IHC WSIs one by one under the microscope, and continuously switching the microscopic field of view magnification to find suspicious cancerous areas, which are classified as 0, 1+, 2+, and 3+ according to the percentage of tumor cell membrane staining and staining intensity score. Here, ERBB2 is linked to gastric cancer.