CD274 and breast cancer: In a recently completed randomized phase II trial (ClinicalTrials.gov Identifier: NCT02924883), the addition of anti-PD-L1 mAb atezolizumab to T-DM1 (trastuzumab covalently linked to the cytotoxic agent DM1) [73] was evaluated in patients with unresectable or metastatic Her-2/neu-positive breast cancer who had received prior trastuzumab- and taxane-based therapy [74] (Table 1).