MAP2K7 and thyroid gland undifferentiated (anaplastic) carcinoma: To test this hypothesis, we tested the effects of lenvatinib with the MEK inhibitor U0126 in vitro using two human anaplastic thyroid cancer (ATC) cell lines, 8505C and TCO1, and with another MEK inhibitor, selumetinib (AZD6244), in an ATC mouse model.