We first validated it by predicting both ex vivo and in vivo responses of a panel of Patient-Derived Tumor Xenograft (PDTX)-derived tumor cells (PDTCs) of breast cancer from the BCaPE database to PARP inhibitors (talazoparib/olaparib).41 Specifically, we selected all PDTCs with either relatively high expression of genes in the panel or HR defects as PARP-sensitive PDTCs. Here, PARP1 is linked to breast cancer.