EWSR1 and Ewing sarcoma: Recently, multiple studies have analyzed the role of NKX2.2 immunopositivity in the diagnosis of ES. NKX2.2, a downstream target of the Ewing sarcoma breakpoint region-Friend leukemia integration 1 (EWSR1-FLI1) fusion, has been identified as a potential stain to differentiate ES and Ewing-like sarcoma from other small round blue cell tumors. In this study, we examine the histopathological interpretation of five patients.