Abstract: The present invention relates to isolated phosphorylated NF45 peptides and isolated phosphorylation site-specific antibody or antigen-binding portion thereof that specifically binds a phosphorylated NF45 protein. The present invention also relates to methods of utilizing these antibodies to determine the therapeutic efficacy of a candidate compound and methods for screening for candidate compounds that increase the phosphorylation of NF45 protein in a cell.

Abstract: The present invention provides a method for determining the efficacy of a c-Met inhibitor in treating a cell proliferative disorder, comprising: a) administering to a subject in need thereof a therapeutically effective amount of the c-Met inhibitor, or a pharmaceutically acceptable salt, prodrug or metabolite thereof, either alone or in combination with a therapeutically effective amount of a second anti-proliferative agent; and b) measuring the concentration of hepatocyte growth factor (HGF) in the serum from the subject, wherein if the concentration of serum HGF does not decrease, or if the concentration of serum HGF increases, the c-Met inhibitor is efficacious in treating the cell proliferative disorder.