PARP1 and cancer: Consequently, despite the fact that PARG has an opposite to PARP activity and may be approached as a means to downregulate pADPr, the majority of published data on PARG focuses on its inactivation [18–21], and, in addition to PARP inhibitors, a number of PARG inhibitors have recently emerged as potential anti-cancer interventions [13,15,22,23], linking the therapeutic effect of PARG inhibitors with the deficiencies in DNA replication [24–26].