<p>Proliferation of endothelial cells was evaluated by double staining for the proliferation marker Ki67 (green) and the endothelial cell marker vWF (red); co-localization of both signals showing as yellow (overlay) The lamina elastica interna shows typical green autofluorescence. At two weeks double positive cells (white arrows) were restricted to the luminal surface in the BAMBI<sup>−/−</sup> mice, whereas at 4 weeks double positive cells also appeared deep in the neointima in a pattern consistent with ongoing neo-vessel formation (original magnification ×1000).</p
