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.