RET and medullary thyroid gland carcinoma: A recent study compared the effects of four TK inhibitors (XL184, vandetanib, sunitinib, and axitinib) on cell proliferation and RET inhibition and looked for mutation specificity using cell lines that harbored a MEN-2A mutation (MTC-TT), a MEN-2B mutation (MZ-CRC-1), or a RET/PTC rearrangement (TPC-1).