PDGFRA and astrocytoma (excluding glioblastoma): In malignant astrocytoma, we recently determined that knockdown of SULF2 resulted in decreased activity of multiple RTK signaling pathways including PDGFR-alpha, IGF1R-beta and EPHA2 [40], three pathways known to be involved in astrocytoma growth and invasion [10, 13, 14, 63-65].