(K) ER (-), PR (-) and HER2 (-) UCD52 patient derived tumor tissue was xenografted in breast fat pad of NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice, following by treatment with IgG1 or KMTR2 (50μg, 4 doses). Harvested tumors were analyzed for PD-L1, CD47 and PARP in lysates. 