Regulation of the cell cycle and radiation reaction.

<p>(<b>a</b>) Overview of the cell cycle regulation, cell responses to environmental factors and radiation. (<b>b</b>) Survival curves for cells in specific cycle phases and with increased radioresistance due to quiescence, as described with the linear-quadratic model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133357#pone.0133357.e014" target="_blank">Eq 5</a>. (<b>c</b>) Dependency of the oxygen enhancement ratio on the local oxygen concentration employed in order to alter the radiation response for hypoxic cells according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133357#pone.0133357.e015" target="_blank">Eq 6</a>, calculated according to equation 8 from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133357#pone.0133357.ref059" target="_blank">59</a>].