PARP1 and central nervous system cancer: In general, high levels of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) are highly involved in the malignancy of gliomas, as well as in chemoresistance due to the activation of different signaling mediators, such as poly(ADP-ribose)polymerase (PARP-1), Mitogen-Activated Protein Kinases (MAPKs), nuclear factor erythroid 2-related factor 2 (Nrf-2) and many others (Figure 1).