CD274 and breast cancer: During the 13·6 (for PD-L1+ tumors) and 12·2 (for PD-L1- tumors) months evaluation period, even though grade 3-5 adverse events (AE) were reported in 50% of patients (with treatment discontinuation due to AE in 8% of the patients), the overall findings suggest that the combination of pembrolizumab and TZ is safe to use and showed continuing clinical benefits in HER2+ BC patients with TZ-resistant and PD-L1+ tumors (47).