RPGRIP1 and retinal degeneration: A recent N-ethyl-N-nitrosourea-induced RPGRIP1 null mouse model (referred to as RPGRIP1nmf247) showed a more severe retinal degeneration when compared to that of RPGRIP1tm1Tili mice. RPGRIP1tm1Tili mice showed a rapid and progressive photoreceptor cell death.