CX3CR1 and retinal degeneration: Similar conflicting reports exist for Cx3cr1−/− mice, with one study attesting to the development of age-related retinal degeneration in Cx3cr1−/− mice (Combadiere et al., 2007) and another more recent report suggesting that this degeneration is not due to the deletion in Cx3cr1, but to discrepancies in the genetic background of the mouse line (Chinnery et al., 2012).