Studies in humans of the genotype distribution of CX3CL1 variants and their association with disease, also show a potential link between CX3CR1-Thr280Met, a variant associated with cell migration deficit, and a higher risk of human age-dependent macular degeneration (AMD) (Tuo et al., 2004; Chan et al., 2005; Combadiere et al., 2007). Here, CX3CR1 is linked to age-related macular degeneration.