PDGFRB and neoplasm: PDGFR signaling has been known for many years to regulate cell migration [36,39] via activation of a number of signaling pathways including small Rho GTPases, phosphatidylinositol (PI)3-kinase and phospholipase (PL)C-γ [36] and in tumor cells this has been linked to activation of PI3-kinase [29,40].