AZD4547 also inhibits recombinant VEGFR2 (KDR) kinase activity with an IC50 of 24 nM. In KG1a, Sum52-PE, MCF7, and KMS11 cell lines, AZD4547 potently inhibits autophosphorylation of FGFR1, 2, and 3 tyrosine kinases (IC50 values of 12, 2, and 40 nM, respectively) and displays weaker inhibition of FGFR4 cellular kinase activity (IC50=142 nM). Significantly weaker inhibitory activity is observed versus cellular KDR and IGFR ligand-induced phosphorylation (IC50 values of 258 and 828 nM, respectively), representing approximately 20- and 70-fold selectivity over cellular FGFR1. Besides, AZD4547 potently inhibits FGFR phosphorylation and downstream signaling affected through FRS2, PLCγ, and MAPK at the cellular level.