How p53 Controls Cancer Rates
The gene p53 is central to biochemical processes governing cancer and aging. From EurekAlert, more on how p53 controls DNA damage: "The body's solution to minimizing mutations is to have no fewer than ten different 'careless' [DNA replication] enzymes. Although this may seem paradoxical - intuitively, more careless enzymes should mean more mutations - each of these enzymes is tailored to deal with certain specific types of DNA damage. This specialization is what keeps the level of mutation, and thus the cancer risk, low. But the existence of this variety of specialist enzymes implies precise regulation of the system - otherwise copying by the careless enzymes might get out of control and lead to an unhealthy proliferation of mutations. ... The main components in this system are the proteins p53 and p21. ... if the functioning of p53 or its relative, p21, is harmed, the activities of the careless enzymes can go into overdrive, leading to more mutations."
Link: http://www.eurekalert.org/pub_releases/2006-05/acft-wis050206.php