“We thank K. V. Ly, L. Fijany, Y. Soda, M. Soda and M. Schmitt for technical assistance; F. d’Adda di Fagagna, S. Minucci, A. Viale, G. Gargiulo and J. Karlseder for discussion and feedback; the Narita, Gage, Burris, Amati and Shaw laboratories, and F. F. Lang for reagents; and the Salk Institute’s Waitt Advanced Biophotonics Center and Gene Targeting and Transfer, and M. Shokhirev and the Razavi Newman Integrative Genomics and Bioinformatics Core. G.S. is supported by the AIRC/Marie Curie International Fellowships in Cancer Research (12298), Istituto Superiore di Sanità, TRAIN ‘Training through Research Application Italian iNitiative’. M.V.P. is supported by the NIH (NIAMS grants R01-AR067273 and R01-AR069653) and a Pew Charitable Trust grant. X.W. is supported by a CIHR postdoctoral fellowship (MFE-123724). I.M.V is an American Cancer Society Professor of Molecular Biology. A.R. is supported by the NCI T32 grant, Salk Women in Science, Salk Excellerators Award and the Stavros Niarchos Foundation New Frontiers Salk Research Specialist Award. M.J.K. is supported by F30 DK112604. A.S. is supported by the NCI Cancer Center Support Grant P30 (CA014195 MASS core) and Dr. Frederick Paulsen Chair/Ferring Pharmaceuticals. This work was supported in part by a Worldwide Cancer Research grant and an American Federation of Aging Research mid-career grant M14322 to S.P. Additional support came from a Cancer Center Core Grant (P30 CA014195-38), the H. N. and Frances C. Berger Foundation, the Glenn Center for Aging Research and the Leona M. and Harry B. Helmsley Charitable Trust (grant #2012-PG-MED002).”