This protein kinase inhibitor (FW = 629.65 g/mol; CAS 890019-63-3; Solubility: 15 mM in DMSO), also known as 5-(3-fluoro-4-(6-methoxy-7- (3-morpholinopropoxy)quinolin-4-yloxy)phenyl)-2-(4-fluorophenylamino)-3-methylpyrimidin-4(3H)-one, targets c-Met, or hepatocyte growth factor receptor (HGFR), a protein tyrosine kinase that plays a key role in several cellular processes and is overexpressed or mutated in different human cancers. AMG-51 shows the enzyme selectivity of c-Met with a (Ki = 4.9 nM), with off-targets, such as IGFR (Ki = 22nM), Ron or Recepteur d'Origine Nantais kinase (Ki = 28nM), and KDR (Ki = 139 nM).