PDGFRB and sarcoma: This present study is the first report describing the in vitro and in vivo efficacy of MGCD516, a novel, broad spectrum small molecule inhibitor that blocks a wide array of RTKs known to be amplified/overexpressed in sarcomas, including c-Kit, PDGFRβ [21], PDGFRα, c-Met, and Axl [9, 19].