Ccl2 deficiency also does not significantly add to the exacerbated retinal degeneration seen in Cx3cr1−/−/Crb1RD8/RD8 mice suggesting that the effects of Ccl2 and Cx3cr1 signalling defects do not act synergistically on the manifestation of the retinal degeneration in Crb1RD8/RD8 mice. Here, CX3CR1 is linked to retinal degeneration.