Figure 4. The role of p53 family members in the prevention of aging. p53 family proteins are involved in different mechanisms after the induction of a DNA damage. A transient block of cell cycle progression gives time to the cells to repair the DNA. Nevertheless, p53 family proteins can also directly affect the DNA repair mechanisms (see text for details). However, if the damage is too extensive or cannot be repaired, p53 family members could trigger either a permanent exit from the cell cycle (senescence) or a cell death program (apoptosis) as mechanisms of defense. The overall result can be read as a check of the genomic stability that protects cells from aging.