TEK and neoplasm: VEGF-C and angiopoietin-2, together with their tyrosine kinase receptors KDR, Flt-4, and TEK, were found to be increasingly expressed in thyroid cancers, especially in the transition from a prevascular to vascular phase, and this was also correlated to the tumor size, nodal invasion, and, along with a reduced expression of TSP-1, to distant metastases [50].