VEGFA and obesity due to melanocortin 4 receptor deficiency: Since VEGF is deeply involved in collateral vessel formation [23,52], the peculiar aspect of vascular resistance to oleic acid described in this study sheds light on the mechanisms potentially involved in the reduction of collateral vessels that has been observed in vivo both in human [11] and in animal obesity [19–22], a phenomenon playing a role in the pathogenesis of cardiovascular events [12–16].