DS-8201 significantly reduced the risk of death in patients with HER2-positive BC compared with TDM-1 [71], and it was also approved by the U.S. Food and Drug Administration (FDA) in May 2022 for patients with HER2-positive metastatic BC who had previously been treated with anti-HER2 therapy and for those who were treated during or within 6 months of neoadjuvant or adjuvant therapy. This evidence concerns the gene ERBB2 and breast cancer.