FLT1 and neoplasm: They are both orally administered small-molecular inhibitors of multiple tyrosine kinases (TKI), involved in tumor progression and angiogenesis including VEGFR-1 (Flt1), VEGFR-2 (KDR), and VEGFR-3 (Flt4), platelet-derived growth factor receptors (PDGFRs), and c-KIT [13, 14].