Figure 2: Antiangiogenesis activity of lenvatinib in human thyroid cancer xenograft models in nude mice. Nude mice bearing tumor xenografts were treated orally once daily with either vehicle or lenvatinib at the indicated doses when tumor volumes reached between 100 and 300 mm3 (day 1). Microvessel density (MVD) was analyzed by immunohistochemical staining of endothelial cells with an anti-mouse CD31 antibody within the resected tumor xenografts as described in Section 2. MVD is expressed as the average number of microvessels per mm2 in 5 regions of interest (ROIs). Each group consisted of 5 mice. Data are shown as means ± SD. compared with vehicle-treated mice. DTC: differentiated thyroid cancer, MTC: medullary thyroid cancer, and ATC: anaplastic thyroid cancer.