TEK and neoplasm: The critical role of TEMs in tumor angiogenesis and vascular remodeling [12, 13, 17] was shown by increased TEM infiltration following administration of anti-angiogenic agents [18] as well as the blocking of the angiogenic factor angiopoietin-2 (Ang2), a Tie2 ligand associated with activated endothelial cells, leading to tumor vasculature regression and arrested tumor progression [19].