WB (peptide competition) analysis of NIH3T3 cells stimulated with PDGF (Lane 2-5) using GTX25452 PDGF Receptor alpha (phospho Tyr742) antibody prior incubated with the non-phosphopeptide corresponding to the immunogen (Lane 3), a generic phosphotyrosine containing peptide (Lane 4), or, the phosphopeptide immunogen (Lane 5) control. The data show that only the immunogen phosphopeptide blocks the signal, demonstrating the specificity of the antibody.