PARP1 and cancer: Inhibiting PARP1, PARP2, and PARP3.6, inhibiting PARP traps the enzyme on damaged DNA, halting the repair process and forming toxic PARP–DNA complexes, and by initiating DNA repair processes such as error-prone NHEJ or alternative end-joining pathways, leading to mutations or chromosomal change, damaging DNA and leading to cancer cell apoptosis and cell death [103].