According to the established 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines2, HER2 positivity is defined by either (a) >10% of tumor cells with intense, complete, and circumferential membranous HER2 immunohistochemistry (IHC) staining patterns (IHC 3+) or (b) weak to moderate membrane staining observed in >10% of tumor cells (IHC 2+) and coupled with a confirmation of HER2 gene amplification. Here, ERBB2 is linked to neoplasm.