Axillary staging may be omitted in Her2+ breast cancer patients who show clinically node-negative disease after neoadjuvant chemotherapy combined with dual anti-Her2 therapy, especially for those with early tumors, strong Her2+ disease, clinically negative lymph nodes before neoadjuvant therapy, and those in whom the primary tumor achieved a complete clinical response. This evidence concerns the gene ERBB2 and breast carcinoma.