Though the vitreous proteome studies have detected several complement proteins such as C3, CFI, CFB, C4A, C4B, C2, C4BPA, CFD, and CFH in PDR subjects (29–32), their expression levels are highly variable among different studies and do not explain their exact involvement in DR pathology as observed earlier in ROP and AMD. Here, CFB is linked to age-related macular degeneration.