The underlying mechanism of association of non-O blood group antigens with CAD has not been defined clearly, however there are reports which show that non-O group subjects have 25% higher levels of factor VIII-vWF complex compared to group O individuals and vWF (von Willibrand factor) is known to have a role in thrombosis by mediating the adhesion of platelets to vascular wall and promoting their aggregation, thereby increasing the risk of CAD.17 Moreover, expression of ABO gene locus is also associated with plasma levels of lipids. This evidence concerns the gene ABO and coronary artery disorder.