In conclusion, although neurodevelopmental disorders characterizing preterm people are due to multiple factors, our mouse study indicates a causal relationship between reduced IGF-1 signaling during a critical period of brain development and aspects of preterm brain disorders similar to those we observed in a pilot study with a small cohort of ex-preterm children devoid of neonatal brain lesions, supporting the rationale for IGF-1 supplementation in preterm newborns. Here, IGF1 is linked to brain disorder.