# FOXO

FOXO proteins (short for Forkhead box O) are key switches in your insulin/IGF-1 pathway. When insulin and IGF-1 signals run low, FOXO enters the nucleus. There it turns on protective genes. These genes handle stress, repair DNA, clean up cells (autophagy), and fight oxidative damage. One member, FOXO3, stands out. Its variants are among the most reliably repeated genetic markers of a long human life. They turn up in people who reach 100, across many ethnic groups.

## Sources

- Willcox et al.. (2008). FOXO3A genotype is strongly associated with human longevity. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.0801030105
- Webb AE, Brunet A. (2014). FOXO transcription factors: key regulators of cellular quality control. Trends in Biochemical Sciences. https://doi.org/10.1016/j.tibs.2014.02.003
- Flachsbart F, Caliebe A, Kleindorp R, et al.. (2009). Association of FOXO3A variation with human longevity confirmed in German centenarians. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.0809594106

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_Canonical: https://longevity-switzerland.com/en/glossary/foxo · Part of Longevity Cities · Updated 2026-06-22_