Desmoplastic Small Round Cell Tumors (DSRCT) is a very rare tumor that arises in de abdomen. DSRCTs are characterized by a single translocation in the genome resulting in a gene fusion. This fusion involves Ewing sarcoma region 1 (EWSR1) and Wilms tumor 1 (WT1). However, the molecular function of this fusion gene remains elusive. An in-vitro system for DSRCT is successfully developed and we use this system to study the molecular function of the EWS-WT1 fusion gene.