Data accumulated from several decades of research on streptozotocin-induced (STZ) type 1 diabetic (T1D) rat models suggest that the Opioid Growth Factor (OGF) - OGF receptor (OGFr) axis is present in the eye and is involved in growth regulation and homeostasis of corneal surface epithelium [8-12]. The gene discussed is OGFR; the disease is type 1 diabetes mellitus.