EWSR1 and rhabdomyosarcoma: Finally, of 81 (52%) renal sarcoma specimens tested, somatic or tumor level molecular alterations (n = 44; 54.3%) were detected only in EWS (n = 26/26; 100%), CCSK (n = 17/38; 44.7%), and rhabdomyosarcoma (n = 1/2; 50%; p = 0.001; Supplemental Table S3).