PARP-1 is required for BER and is implicated in genome-wide and locus specific active DNA demethylation in part through epigenetic regulation of TET146. Using a PARP-1 inhibitor, DPQ, we observed a dramatic decrease in AREG and EREG expression in Panc1-3D7 cells (Fig. 6F). However, in Panc1-2G6 cells, expression of AREG and EREG was relatively unaffected by PARP-1 inhibition (Fig. 6E), indicating that PARP-1 is mediator of AREG and EREG induction regulated by the integrin α6β4.