In the Trastuzumab for Gastric Cancer trial, trastuzumab (Roche Diagnostics, Basel, Switzerland)—a humanized anti-HER2 monoclonal antibody—increased the survival rate of patients with HER2-positive gastric cancers when administered in combination with chemotherapy [16], and was also approved for the treatment of breast cancers [17, 18]. This evidence concerns the gene ERBB2 and breast carcinoma.