Burggraaf et al. found that thyrotoxicosis increased the plasma levels of most endothelial marker proteins, such as vWF, tissue plasminogen activator (t-PA), PAI-1, and thrombomodulin, and of some liver-synthetized proteins [86], highlighting that in cases of thyroid hormone excess, there is also an endothelial activation, which might contribute to the thrombotic risk. This evidence concerns the gene SERPINE1 and thyrotoxicosis.