Background: Human platelet-derived growth factor (PDGF) receptor is a receptor tyrosine kinase whose activity induces various signalling cascades leading to cell growth and proliferation. Two major isoforms exist, PDGF receptor-α, and PDGF receptor-β,. PDGF receptor-β, can only bind two specific PDGF isoforms, PDGF-β, and PDGF-Δ, (1,2). Upon ligand binding, the receptor undergoes autophosphorylation, allowing binding and activation of cytoplasmic SH2 domain-containing signal transduction molecules such as PI kinase (3), Grb2, and Src, among others. Both Tyrosine 751 and 740 is required for PDGFR-β, mediated PI3 kinase activation. In particular, Tyrosine 751 is the docking site for P13 kinase (4).