The cell cycle is the system through which a cell grows and divides. It is also how a cell passes its DNA to its progeny and is why the cell cycle ceases if the DNA is damaged, as otherwise it risks passing this damage to daughter cells. Scientists at the Nara Institute of Science and Technology (NAIST) have reported a new molecular mechanism that explains how this cessation occurs. The study, which can be read in Nature Communications, shows the transcription factor family MYB3R prevents progression to the division stage (M phase) of the cell cycle in Arabidopsis, a small flowering plant that is a member of the mustard family.