FN1 and Ewing sarcoma: Specifically, we identified that the expression of c-Jun and c-Fos in Ewing sarcoma cells is sufficient to upregulate the expression of multiple proteins, including fibronectin 1 (FN1), vinculin, vimentin, and fibroblast associated protein (FAP), that are downregulated by the EWS-FLI1 oncoprotein.