Previously, in September 2008, an American research team led by Bradley J. Willcox had published in PNAS a study that indicated a higher frequency of this genetic variation in long-lived Americans of Japanese origin (ages 95 and above). Professor Almut Nebel, the scientific leader of the "Research Group for Healthy Ageing" at Kiel, comments: "That published result is only of scientific value if it can be confirmed in a study with an independently chosen sample population. Without that there must still remain a tinge of doubt. We have now eliminated that uncertainty about the connection between FOXO3A and longevity, both by our results from the German sample study and by the support from our French partners in Paris, whose research on French centenarians showed the same trend. This discovery is of particular importance as there are genetic differences between Japanese and European people. We can now conclude that this gene is probably important as a factor in longevity throughout the world."