Cell death after irradiation: How, when and why cells die

The successful use of radiation to treat cancer results primarily from its ability to cause the death of individual tumour cells. The biological consequences of irradiation, including cell death, are highly influenced by pathways within the DNA damage response (DDR) system. The DDR influences not only the sensitivity of cells to death following irradiation, but also the type of cell death that occurs, and the timing of when cell death occurs. Because the DDR differs among different types of normal and tumour cells (and likely even within different populations of tumour cells), the manifestation of cell death can also differ widely among different cell types.