C9 and age-related macular degeneration: According to large genetic studies, strong evidence emerged that more genetic variants are also associated with AMD, such as CFH-related proteins (CFHR1 and CFHR3), complement component 3 (C3), complement factor I (CFI), complement component 2 (C2), complement factor B (CFB), and complement component 9 (C9) [117,118,119,120].