BCO2 and age-related macular degeneration: The genetic variants associated with AMD were located in genes involved in (1) cholesterol and carotenoid membrane transport proteins in the intestine and retina (SCARB1, NPCL1L1, and ABCA1) and/or high-density lipoprotein levels in the bloodstream (SCARB1, APOE, and ABCA1); (2) carotenoid cleavage enzymes (BCMO1 and BCO2); (3) omega-3 fatty acid status (FADS2); and (4) an inherited retinopathy characterized by the complete absence of macular pigment (ALDH3A2) [96].