# IGF-1 signaling

IGF-1 signaling refers to the cascade triggered when insulin-like growth factor 1 binds the IGF-1 receptor, activating parallel PI3K/AKT and MAPK/ERK branches that promote cell growth, proliferation, and protein synthesis while suppressing FOXO-driven stress resistance. IGF-1 can also engage insulin/IGF-1R hybrid receptors at lower affinity. Reduced IGF-1 signaling extends lifespan in worms, flies, and mice, and lower circulating IGF-1 is observed in some long-lived human cohorts. The trade-off between growth/repair benefits and longevity costs remains actively debated.

## Sources

- Kenyon C, Chang J, Gensch E, Rudner A, Tabtiang R. (1993). A C. elegans mutant that lives twice as long as wild type. Nature. https://doi.org/10.1038/366461a0
- Kenyon CJ. (2011). The first long-lived mutants: discovery of the insulin/IGF-1 pathway for ageing. Philosophical Transactions of the Royal Society B. https://doi.org/10.1098/rstb.2010.0276

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_Canonical: https://longevity-germany.com/en/glossary/igf-1-signaling · Part of Longevity Cities · Updated 2026-01-15_