PARP1 and cancer: Significant attempts had been made to acknowledge the brain pharmacokinetics of PARP inhibitors, and many PARP inhibitors, particularly the trapping agents like rucaparib and talazoparib, exhibit efflux liabilities around the BBB, and thus a complete absence of sensitizing response is observed in orthotopic models of tumor in spite of great activity in heterotopic cancer models (Hopkins et al., 2015; Parrish et al., 2015).