A dysfunction of normal vascular endothelial cells to keep high fibrinolytic activity by secreting and retaining tPA on their surface and a suppression of fibrinolytic potential due to the increase in plasma PAI-1 level under many pathological conditions including inflammation, obesity, hyperlipidemia, and aging are considered to impair fibrinolysis and cause thrombogenicity17. This evidence concerns the gene SERPINE1 and obesity due to melanocortin 4 receptor deficiency.