Figure 1. Possible mechanism(s) of ATM inhibitor-mediated mp53 radiosensitization. See text for explanation. For simplicity, focus is on ATM signaling nodes. Abbreviations: ATMi, ATM kinase inhibitor; IR, ionizing radiation; MK2i, MK2 inhibitor; p38i, p38 MAP kinase inhibitor. Arrows denote activation and “T”s dephosphorylation/inhibition. Shapes outlined in red denote phosphorylation events. Adapted from references 14 and 16.