In high-incidence countries, such as Japan and Korea, multiple biomarkers, including Her2, MMR proteins, EBV, PD-L1, EGFR, FGFR2, and CLDN18.2, are routinely evaluated by means of immunohistochemistry or in situ hybridization in all GC patients [17]. The gene discussed is ERBB2; the disease is gastric cancer.