ERBB2 and neoplasm: While the necessity to retest the HER2 status of residual tumors after NAC to tailor the utilization of anti-HER2 therapy is being emphasized [14], the possibility always lost sight that synchronous nodal metastases, distant micrometastases, and even CTCs, if any, which originate from the HER2 positive primary tumor, may still harbor tumor cells that are HER2-gene amplified.