Lenvatinib is an oral multi-tyrosine kinase inhibitor (TKI) that acts on vascular endothelial growth factor receptors 1–3 (VEGFR1-3), fibroblast growth factor receptors 1–4 (FGFR1-4), platelet-derived growth factor receptor-α (PDGFRα), and RET and KIT proto-oncogenes, and is involved in a marked improvement of disease control, as well as with radioiodine-refractory differentiated thyroid cancer [[5], [6], [7], [8], [9], [10]]. Here, FGFR1 is linked to differentiated thyroid carcinoma.