Since the superior OS results of the TOGA trial with adding trastuzumab to first-line chemotherapy in patients with Her2-positive tumors (immunohistochemical expression level 3+ or 2+ combined with positive FISH-verification of HER2 gene amplification), trastuzumab was established as standard therapy in combination with chemotherapy in the first-line setting for Her2-positive patients with advanced or metastatic disease. This evidence concerns the gene ERBB2 and metastatic neoplasm.