The majority of these tumors harbor the t(11;22) translocation and express the fusion protein EWS-FLI.     ///    EWS-FLI alters the morphology of mesenchymal cells and prevents lineage specification.     ///    "In this report, we demonstrate that FLI sequences within EWS-FLI are responsible for interactions with Runx2. "    ///    "We recently showed that EWS-FLI binds Runx2, a master regulator of osteoblast differentiation. "    ///    EWS-FLI blocks the expression of osteoblastic genes in a multipotent progenitor cell line that requires Runx2 to integrate bone morphogenic protein (Bmp)2 signaling while increasing proliferation and altering cell morphology.     ///    These results demonstrate that EWS-FLI blocks the ability of Runx2 to induce osteoblast specification of a mesenchymal progenitor cell.     ///    "The Ewing's sarcoma fusion protein, EWS-FLI, binds Runx2 and blocks osteoblast differentiation.. "