The APTneo trial (NCT03595592) is evaluating, in patients with HER2-positive high-risk or locally advanced early breast cancer, the addition—in the neoadjuvant setting—of atezolizumab to the combination of trastuzumab, pertuzumab, carboplatin, and paclitaxel, with the primary endpoint being event-free survival (EFS). Here, ERBB2 is linked to breast cancer.