The tyrosine kinase inhibitor (TKI) vandetanib, a selective inhibitor of wild-type rearranged during transfection (RET) kinase as well as of vascular endothelial growth factor receptor (VEGFR) signaling [1–3], has demonstrated a favorable disease control in patients suffering from advanced medullary thyroid carcinoma (MTC) [4, 5]. Here, KDR is linked to medullary thyroid gland carcinoma.