Given that Cox2 activity has been linked to increased tumor angiogenesis, we also stained tumor sections with the endothelial cell marker CD31 and observed a significant increase in CD31+ blood vessels in tumors of 1638N/Bcat and Min/Bcat mice, but not in tumors of Ras/Bcat mice (Fig. 6C-F). Here, PECAM1 is linked to neoplasm.