From ScienceDaily: researchers "have found that the level of a single protein in the tiny roundworm C. elegans determines how long it lives. Worms born without this protein, called arrestin, lived about one-third longer than normal, while worms that had triple the amount of arrestin lived one-third less. ... arrestin interacts with several other proteins within cells to regulate longevity. The human version of one of these proteins is PTEN, a well-known tumor suppressor. ... The links we have found in worms suggest the same kind of interactions occur in mammals although human biology is certainly more complicated. We have much work to do to sort out these pathways, but that is our goal. ... We don't know at this point if human arrestins regulate PTEN function or if anything happens to arrestin levels during the development of cancer. Do increasing levels turn off more PTEN, thus promoting cancer, or do levels decrease and allow PTEN to be more active? ... If it turns out to be the first scenario - that increasing amounts of arrestin turn off the tumor suppressor activity of PTEN, then it may be possible to selectively inhibit that process. We have some interesting work ahead."