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Our study demonstrates a female-specific association of an EXO1 promoter SNP with longevity. Such sex-specificity is not surprising since gender is a major determinant of longevity, favoring women. It also accounts for important differences in the frequency of various age-related diseases. There is a distinct prevalence of women among long-lived individuals, reaching up to 85% in some populations of centenarians and super-centenarians (Perls and Terry, 2003). It has been suggested that the mortality rates in men and women follow different trajectories during aging and that a complex interaction of environmental and genetic factors is likely to affect the gender-specific probability of reaching old age (Candore et al., 2006; Franceschi et al., 2000).

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