CD274 and breast cancer: In the BrEAsT study, three single-arm, phase Ib trials on patients with advanced-stage breast cancer study the combination of BN-brachyury along with T-DM1 (adotrastuzumab emtansine), entinostat (histon deacetylase inhibitor), and M7824 (Bintrafusp-α, bifunctional fusion protein targeting both TGF-β and PD-L1).