Two very different roles were reported for the protein REST last week. In adults, REST activation appeared to extend lifespan by reducing overall brain activity. Principal investigator Bruce Yankner, professor of genetics at Harvard Medical School and co-director of the Paul F. Glenn Center for the Biology of Aging, told BioWorld that in postmortem brain samples of individuals who had had no cognitive impairments at the time of their death, his team found "a correlation between down-regulation of excitation and extended longevity."