BCOR and sarcoma: The 2020 World Health Organization (WHO) Classification of Tumors of Soft Tissue and Bone distinguished undifferentiated small round cell sarcomas as a separate group of malignancies which include Ewing sarcoma, round cell sarcoma with EWSR1-non-ETS fusion, CIC-rearranged sarcoma, and sarcoma with BCOR genetic alteration [2].