Some studies have focused on investigating the characteristics of round cell undifferentiated sarcomas, demonstrating that these tumors can be categorized into Ewing sarcoma, round cell sarcoma with EWSR1-non-ETS fusions, CIC-rearranged sarcoma, and sarcoma with BCOR genetic alterations (Fletcher, 2014). Here, EWSR1 is linked to Ewing sarcoma.