Given the reports of reduced circulating concentrations of GH and IGF-1 in children with LPI that also suffer from growth failure (Goto et al., 1984; Esposito et al., 2006; Evelina et al., 2015; Al-Qattan et al., 2021; Niinikoski et al., 2011), we assessed the plasma concentrations of IGF-1 in our Slc7a7Lbu/Lbu mouse model. This evidence concerns the gene IGF1 and Growth delay.