[1] Buck Inst Age Res, Novato, CA 94945 USA
[2] Univ So Calif, Dept Biol Sci, Program Mol Biol, Los Angeles, CA 90089 USA
[3] Univ So Calif, Ethel Percy Andrus Gerontol Ctr, Los Angeles, CA 90089 USA
[4] Univ So Calif, Keck Sch Med, Res Ctr Liver Dis, Div Gastroenterol & Liver Dis, Los Angeles, CA 90033 USA