On the basis of MNU-induced retinal degeneration model caused by photoreceptor-specific cell loss, as confirmed again by the dramatic disruption of ONL morphology, we discovered that expression of NDRG2 in the photoreceptor IS/OS layers was specifically reduced, to an extent that is almost comparable to the background level (Fig. 6a). This evidence concerns the gene NDRG2 and retinal degeneration.