Many of Double Strand Break Repair (DSBR) proteins accumulate in the vicinity of the break site, forming so-called radiation-induced foci that can be visualized by immunofluorescence or live-cell imaging methods. The timing and type of proteins recruited to the DSB defines the downstream functions of DDR pathways which range from signaling to DSB repair, cell cycle arrest or apoptosis. This differential protein recruitment thus decides the fate of a cell following DSB.

Resistance to radiation is a major challenge in the treatment of Glioblastoma. A subset of tumor cells is capable of modulating their DNA damage repair pathway to escape apoptosis, mechanisms of which are still unknown. Since the physiological substrate of DNA damage repair machinery is packed into chromatin, the efficiency of DNA damage repair in a cell must depend on how well the repair factors can gain access to the damaged DNA. Histone modification and chromatin re-modelling are the most important determinants of DNA accessibility.