Similar to the poor survival and growth deficits in the Slc7a7-deficient mouse models (Stroup et al., 2020; Sperandeo et al., 2007; Bodoy et al., 2019), global Igf1−/− and Igf1r−/− mouse models with depleted circulating IGF-1 concentrations manifested early lethality (due to respiratory failure) and growth failure (27-60% of WT body weights) (Liu et al., 1993; Powell-Braxton et al., 1993; Wang et al., 2006; Mohan et al., 2003). This evidence concerns the gene IGF1R and respiratory failure.