In MFS, a complex regulation of angiogenesis has been observed; indeed, an analysis of 43 MFS cases demonstrated that intratumoral microvessel density (assessed by CD31 staining) increases proportionally with histological grade, correlating with VEGF and with mRNA expression of its receptors, as well as with elevated levels of thrombospondin−1 and collagen I (13). This evidence concerns the gene VEGFA and Marfan syndrome.