Cediranib (AZD2171) is a highly potent (IC50 < 1 nmol/L) ATP-competitive inhibitor of recombinant KDR tyrosine kinase in vitro, also inhibits Flt1/4 (IC50: 5 nM/≤3 nM), similar activity against PDGFRβ and c-Kit, selective more for VEGFR than PDGFR-α (36-fold), CSF-1R (110-fold), and Flt3 (1000-fold) in HUVEC cells.