IGF1 and hyperinsulinemic hypoglycemia, familial, 4: To corroborate the dependence of OR5H2 gene expression on the circulating IGF1 levels, the expression of olfr196 mRNA (the mouse orthologue of OR5H2) was measured in two different animal models: (1) the GHRKO (‘Laron’) mouse, an animal model of IGF1 deficiency, and (2) bGH transgenic mouse, overexpressing the bGH gene.