BDNF and IGF-1 are essential in neuronal differentiation and survival (Rossi et al., 2006; Zhang et al., 2014), and both T1D and T2D models have been reported to have reduced BDNF levels (Nakagawa et al., 2000; Stranahan et al., 2009). The gene discussed is IGF1; the disease is type 1 diabetes mellitus.