The Editors of Aging Cell wish to congratulate the winners of our Annual ‘Best Paper’ Competition. This is the second year in which we have asked the members of the Editorial Board to nominate papers published the previous year (Volume 8), that they consider have contributed to the advance of our understanding of a fundamental process in biology of aging, or that have resolved controversial aspects of aging research. The Editors-in-Chief cast their ballots to select the winner and two runners-up out of the 16 papers nominated by the members of the Editorial Board. The winning paper of our second Annual Best Paper competition is: ‘Anti-aging activity of the Ink4/Arf locus’ from Manuel Serrano and his team composed of Ander Matheu, Antonio Maraver, Manuel Collado, Isabel Garcia-Cao, Marta Canamero, Consuelo Borras, Juana Flores, Peter Klatt and Jose Viña. This work appeared as Aging Cell 8: 152-161 in 2009. A free copy is available from Wiley-Blackwell at their Online Open site at http://www3.interscience.wiley.com. In this work, Dr. Serrano and his group have directly analyzed the global impact on organism aging and longevity of an increase in the expression levels of the Ink4/Arf locus. This locus that encodes for the well known tumor suppressors p15 p19 and p16, has been linked to different age-associated diseases and to frailty in humans, but the direct consequences of the increased expression observed during aging have not been previously analyzed. Using elegant genetic mouse models, Serrano’s group demonstrated that increased gene dosage of this locus extended median longevity independently of the effect of this locus in protection against cancer. Their study supports the idea that the Ink4/Arf locus, by promoting quiescence and preventing unnecessary proliferation, has a global anti-aging effect. In fact, the authors propose that ‘it is conceivable that the upregulation of the Ink4a/Arf locus during aging reflects a protective response elicited by an aberrant or unbalanced mitogenic milieu.’ Dr. Matheu, as first author of this work, will receive a year’s subscription to Aging Cell, and the right to give free 1-year subscriptions to four of his colleagues of choice. He will also receive a Prize Certificate from our sponsors, the Anatomical Society of Great Britain and Ireland. Two other papers nominated by our Editorial Board came very close to winning Paper-of-the-Year. These were the work of Eric Greer and Anne Brunet entitled ‘Different dietary restriction regimens extend lifespan by both independent and overlapping genetic pathways in C. Elegans’, which appeared as Aging Cell 8: 113–127 in 2009, and the work of Rong Yuan and colleagues in Beverly Paigen's group entitled ‘Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels’, which appeared as Aging Cell 8: 277–287 in 2009. Dr. Greer’s work presents a comprehensive and rigorous comparative study of the mechanisms behind lifespan extension in worms in response to different dietary restriction regimens to conclude that different regimens extend lifespan by mostly independent genetic mechanisms. Dr. Yuan’s elegant study using 31 genetically-diverse inbred mice presents convincing support for the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice. Both will receive a year’s subscription to Aging Cell for the first author and one for a nominated colleague. Congratulations to the members of these three teams for such superb contributions and thank you to all the groups interested in aging research for continuing to send some of their best work to Aging Cell for review. Next year’s winner could be you!