TEK and medullary thyroid gland carcinoma: Only a few of these kinase inhibitors are approved drugs: lapatinib (breast cancer targeting HER2), sorafenib (renal cell carcinoma, multikinase inhibitor), vandetanib (medullary thyroid cancer, multikinase inhibitor) and regorafenib (metastatic colorectal cancer, VEGFR2-TIE2 inhibitor).