As amplification and overexpression of the human epidermal growth factor receptor 2 (HER2) gene is an established therapy target in esophageal cancers, we performed immunohistochemical staining for HER2 expression on formalin-fixed and paraffin-embedded tissue sections, which indicated an overexpression in the two distinct brain metastases of patient BM36 (Fig. 1D). The gene discussed is ERBB2; the disease is esophageal cancer.