Combination treatment prolonged the survival of mice via MAPK signaling pathway blockade.347 Although patients could significantly benefit from lenvatinib (E7080, multitarget inhibitor, mostly for VEGFR-2 (KDR)/VEGFR3 (Flt-4)), the adverse effect of lenvatinib was not tolerated in patients with radioiodine-refractory thyroid cancer.348 Lenvatinib plus the MEK inhibitor selumetinib (AZD6244) promoted the anticancer effect in mice with anaplastic thyroid cancer. This evidence concerns the gene FLT4 and thyroid gland undifferentiated (anaplastic) carcinoma.