The cytotoxicity induced by continuous release of heme in circulation, as in thalassemic and SCD suffering individuals, is apparently the leading cause of CVD, a belief also confirmed by the protective effect of the Hb/heme scavenger Hp and the heme degrading enzyme heme oxygenase 1 (HO-1) in the development of these pathologies. This evidence concerns the gene HP and Schnyder corneal dystrophy.