PARP1 and neoplasm: Our previous results, which firmly proved that the inhibition of PARP-dependent PARylation (the covalent attachment of poly-ADP-ribose units to acceptor proteins) activates TET enzyme and hydroxy/demethylation in NIH3T3 cells (Tolić et al., 2022), provided a rationale for the hypothesis that DNA hydroxy/demethylation boosted by PARP inhibition could restore tumor sensitivity via TET activation.