FACS analysis of single cell suspensions of disaggregated MCA/129 fibrosarcomas grown in asmase+/+ and asmase−/− mice revealed similar numbers of CD31+/VEGFR2+ endothelial cells (Figure S13), and immunohistochemistry revealed that the vasculature of fibrosarcomas grown in asmase−/− mice displays a normal pattern of VEGFR2 expression, and normal VEGFR2 tyrosine phosphorylation upon intravenous VEGF injection (data not shown). Here, PECAM1 is linked to fibrosarcoma.