From previous studies, it appears that many genotypes are associated with human longevity in a gender-specific fashion, leading to the hypothesis that men and women follow different strategies to attain longevity (Bonafe` et al. 2001; De Luca et al. 2001; Barbieri et al. 2004; Cederholm et al. 2007). In this case, we did not observe any significant difference between the two genders, and the frequency distribution of the genotypes was remarkably similar in all subjects. The difference in sample size between men and women is likely a matter of the number of subjects in the two groups (women in population aging studies usually outnumber men) rather than a real biological difference. In any case, we detected a significant increase of the heterozygous Klotho genotype in the class of elderly people, but not in the class of long-living people. On the whole, these results show that the heterozygous genotype exerts a beneficial effect on survival when population mortality begins to accelerate (Ukraintseva and Yashin 2001), indeed it is found to be more frequent in the group of people aged from 66 to 91 years, while, on the contrary, in the group of long-living people its frequency is nearly identical to that of young people. Thus, the KL-VSReceptor (PPAR) gamma with longevity. Exp Gerontol: doi: /j.exger. Bartke A (2006) New findings in transgenic, gene knockout, and mutant mice. Exp Gerontol: doi: /j.exger. Bonafè M, Olivieri F, Cavallone L, Giovagnetti S, Maiyegiani F, Cardelli M, Pieri C, Marra M, Antonicelli R, Lisa R, Rizzo MR, Paolisso G, Monti D, Franceschi C (2001) A gender-dependent genetic predisposition to produce high levels of IL is detrimental for longevity. Eur J Immunol: doi: / Bonafè M et al. (2002): Polymorphisms in cytokine genes influence long-term survival differently in elderly male and female patients. J Intern Med: doi: /j.x

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