The relationship between HER2 protein overexpression and/or gene amplification and prognosis in GC and EGJC have been described in several reports; however, studies have reported poor prognosis [6–9], absence of a relationship with prognosis [10, 11], and good prognosis [10, 12], and the assessment of which is controversial. The gene discussed is ERBB2; the disease is gastric cancer.