These observations are consistent with a recent finding of the morphological preservation of a few of On and Off RGCs with the largest soma diameters in the rd1 retina [24], as well as with the observation in another mouse model of RP, rd10 mouse, which carries a missense mutation in the Pde6b gene and has a slower course of degeneration [23]. The gene discussed is PDE6B; the disease is retinitis pigmentosa 1.