EWSR1 and Ewing sarcoma: With the emerging family of non-Ewing undifferentiated small round cell sarcomas of bone and soft tissue, including sarcomas with CIC-rearrangements, BCOR-alterations, and EWSR1-non ETS fusions, recognition of these complex and cryptic EWSR1 fusions/rearrangements in ES is both diagnostically and prognostically valuable and often requires a multimodal molecular approach [13,14].