To capture unique phosphosites in HER2-positive gastric cancer, we overlaid the phosphoproteomic data from the pre-treatment HER2-positive and HER2-negative T groups with phosphosites in the ErbB signaling pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database (Fig. 3, Table S5). The gene discussed is ERBB2; the disease is gastric cancer.