PARP1 and cancer: The proteins included key apoptosis, cell cycle, and growth factor signaling regulators associated with cancer pathogenesis, such as the anti-apoptotic proteins BCL-2 and BCL-XL [28], apoptotic effector caspases 3 and 9 [29], cell cycle promoting CDKs 2 and 6, growth factor receptors EGFR and VEGFR [30], tumor suppressor p53 [31], and the DNA repair protein PARP-1 [32].