Cell-cycle regulation is a major functional class of G64 genes.

<p>A total of 40 genes in the G64 module were mapped to cell-cycle genes in CycleBase (<a href="http://www.cyclebase.org/" target="_blank">http://www.cyclebase.org/</a>). Each of the 40 cell-cycle genes was accordingly allocated to one of the cell-cycle stages (e.g., G1, S, G2, or M, colored in yellow, green, blue, and red, respectively).