Soft tissue sarcomas with Ewing Sarcoma Breakpoint Region 1-POZ/BTB and AT Hook Containing Zinc Finger 1 (EWSR1-PATZ1) gene fusion represent a recently recognized subgroup of "round cell sarcomas with EWSR1-non-ETS fusions." These tumors exhibit diverse morphologic features and a polyphenotypic immunoprofile, often co-expressing neural and skeletal muscle markers. This evidence concerns the gene PATZ1 and Ewing sarcoma.