Rats administered STZ have shown reduced insulin receptor signaling in the retina, especially in retinal endothelial cells, which may contribute to the early progression of diabetic retinopathy (Aizu et al., 2002; Fort et al., 2011; Kondo and Kahn, 2004; Reiter et al., 2003). The gene discussed is INSR; the disease is diabetic retinopathy.