REEP6 and retinal degeneration: The homozygous L135P mice displayed retinal degeneration, including thinning of the outer nuclear layer (ONL) and reduced response to light in dark-adapted animals observed at 4 months of age, confirming potential pathogenicity and the importance of REEP6 for retinal homeostasis (19); however, REEP6 was still detectable at significant levels in the retina of the L135P homozygous mice, and could potentially have some residual activity.