The cell cycle and cancer

Recent findings have demonstrated an intimate relationship between cell cycle control and tumorigenesis. Various genes encoding regulatory activities that govern the mammalian cell cycle, particularly the progression of quiescent cells through G1 and into S phase, are targets for genetic alterations that underlie the development of many human neoplasms. These include members of the cyclin gene family as well as members of a recently identified class of cell cycle regulators, the cyclin-dependent kinase inhibitors. Moreover, both the Rb and p53 tumor-suppressor proteins have been found to regulate products of the cell cycle machinery and be regulated by them, further demonstrating the link between the cell cycle and cancer.