...compare the efficiency of four recently developed TK inhibitors, XL184, vandetanib, sunitinib, and axitinib, using three cell lines: MTC-TT reported to be derived from a sporadic MTC expressing a C634W RET mutation, MZ-CRC-1 derived from a patient with metastatic sporadic MTC expressing an M918T RET mutation, and TPC-1 derived from a patient with PTC expressing a RET/PTC-1 rearrangement....XL184 being the most potent inhibitor in MEN2A and PTC and vandetanib the most effective in MEN2B in vitro.