Susceptibility to aging and susceptibility to cancer are viewed as a balance, centered around the disposition of multipurpose biochemical machinery like the p53 gene. You can tilt the mechanism one way or another - less cancer or slower aging - but not both at once. This Nature publication throws that out of the window - it seems it is possible to tinker p53 into providing slower aging and less cancer. "The conclusion seems to stand in direct contradiction to previous work, which showed that a boost in p53 kept mice cancer free but also caused them to age more quickly. But there's a key difference between these studies, the researchers say: in the new work, the normal regulatory mechanisms remain in place, so p53 is churned out only when needed. This seems to turn an ageing protein into a youth-preserving one. It's a very impressive effect. It's very hopeful because it says under some circumstances you can get the best of both worlds. ... These mice produce more p53 protein when prompted to by cellular stress, such as DNA damage or lack of oxygen. As expected, mice with the extra copy of p53 had fewer tumours than regular mice, and their cells were less likely to turn cancerous when grown in a Petri dish. On average, the transgenic mice lived 16% longer than normal mice."