The growth and reproduction of all living organisms are
dependent on the cell cycle, the process which leads to cell division.
Uncontrolled division of cells is important for disease particularly
cancer. Two events, S-phase and mitosis, are common to all cell cycles and
are necessary for the two newly divided cells to receive a full complement
of genes. The onset of S-phase and mitosis are controlled by cyclin
dependent kinases (CDLKs) in all eukaryotes studied from yeast to human
beings. Checkpoints controls operate which block cell cycle progression if
DNA is damaged or incompletely replicated which work through the CDKs and
have been implicated in the development of cancer.