Purified Hp was subsequently shown to be angiogenic in two in-vivo models.12 Results from animal models of myocardial ischemia have implicated the Hp protein in coronary collateral development.13 The Hp 2-2 protein appears to have a greater potency than Hp 1-1 as deduced from genotype studies of patients with peripheral arterial occlusive disease.14 It was this angiogenic function of Hp which ultimately led to our studies linking Hp to diabetes, as will be described below. Here, HP is linked to myocardial ischemia.