A consistent increase in VEGF, VEGF-C, and angiopoietin-2 and their tyrosine kinase receptors VEGFR2, VEGFR3, and TEK receptor tyrosine kinase have been demonstrated in thyroid cancer versus normal thyroid tissues, and a strong correlation has been found between this overexpression and tumor size [50]. This evidence concerns the gene NTRK1 and neoplasm.