oxygen
Figure 10.14 The role of normal p53 is to monitor DNA and the supply of oxygen hypoxia is a condition of reduced oxygen supply . If damage is detected, p53 triggers repair mechanisms. If repairs are unsuccessful, p53 signals apoptosis. A cell with an abnormal p53 protein cannot repair damaged DNA and thus cannot signal apoptosis. Cells with abnormal p53 can become cancerous. credit: modification of work by Thierry Soussi .