Transcripts of several complement components involved in the classical pathway (C1QB, C1R, C1S), common to both the classical and alternative pathways (C3, C5, C7), and inhibitors and regulators of both pathways (CD55, CD59, CFI and CFH) were upregulated in advanced stages of rcd1 and xlpra2 retinal degeneration. This evidence concerns the gene CD55 and retinal degeneration.