Researchers have known for a few years that the TOR gene is important in calorie restriction and other related ways of extending healthy life. Recent research follows the chain of biochemical cause and effect beyond TOR: "In C. elegans, the tiny roundworm that our lab studies, as well as some other animals, a loss of TOR has been shown to slow aging. Our work with C. elegans reveals that TOR depends on a second gene called pha4/FoxA to control the aging process ... When there's lots of food, TOR gets active, which decreases the action of pha4/FoxA down the line, and that in turn shortens the lifespan of C. elegans. When there's little food, there's little TOR and more pha4/FoxA, and that results in a longer lifespan. ... Many organisms have a TOR gene and a gene similar to pha4/FoxA, such as single-cell yeasts, roundworms, and mammals including humans. In mammals, FoxA controls cell metabolism and there is a lot of it in breast and prostate cancers. The findings of this research establish that animals use both genes to sense the amount of food that is available and control the length of lifespan. Further research will be required to establish whether a similar relationship between these factors can control metabolism, longevity or disease in humans."