This strongly suggested that the early onset, inferior retinal degeneration characterised by the appearance of the typical disciform autofluorescent lesion in the inferior retina is caused by a third genetic locus, that leads to a typical retinal degeneration phenotype and indicates that the original CCDKO double knockout mouse line for Ccl2 and Cx3cr1 actually contains a third autosomal recessive retinal degeneration locus. This evidence concerns the gene CCL2 and retinal degeneration.