ERBB2 and breast cancer: Trastuzumab/Pertuzumab/hyaluronidase injection is a subcutaneously administered combination therapy of pertuzumab and trastuzumab, which is indicated for the neoadjuvant treatment of HER2+, locally advanced, inflammatory, or early-stage BC, and adjuvant treatment of HER2+ early BC with an elevated risk of recurrence [49].