Genetic studies of human patients with hypogonadotropic hypogonadism and anosmia, Kallman’s Syndrome, have identified a variety of molecules that influence GnRH neuronal migration and/or olfactory development (Wray, 2010; Topaloglu, 2017; Bouilly et al., 2018). This evidence concerns the gene GNRH1 and Kallmann syndrome.