According to the 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines, HER2 status is assessed by immunohistochemistry (IHC), which measures HER2 protein levels on the tumor cell membrane, and/or by fluorescence in situ hybridization (FISH), which measures HER2 gene amplification.5 This evidence concerns the gene ERBB2 and neoplasm.