For metastases, while there are data that acute use of anti-endoglin [47] or anti-ALK1 antibodies [48] attenuate endothelial sprouting and other early angiogenic processes, recent data suggest that long term deficiency may render endoglin deficient mice at enhanced risk of tumour metastatic spread [49], and that endoglin overexpression may be protective [50]. This evidence concerns the gene ENG and neoplasm.