FLT4 and myelodysplastic syndrome: Lenalidomide, a 4-amino-glutamyl analogue of thalidomide, is used to treat multiple myeloma (MM) [58] and myelodysplastic syndromes (MDS) [59], and also lenvatinib, which acts as a multiple kinase inhibitor against the VEGFR1, VEGFR2, and VEGFR3 kinases, is applied for the treatment of thyroid cancer [60].