Figure 1.

Schematic representation of the DNA damage response (DDR). Cells are constantly exposed to various environmental or endogenous genotoxic agents. Through the DDR pathway, the DNA damage is recognized by sensor protein complexes. The accumulation of DNA damage provokes various cellular events, including cell cycle arrest, DNA repair, cellular senescence, or cell death. The DDR plays a key role in the genomic stability that protects cells from tumorgenesis. UV, ultraviolet; IR, ionizing radiation; ROS, reactive oxygen species.