PROM1 and Ewing sarcoma: In addition, we found that high PROM1 expression was associated with poor OS in patients with esophageal cancers and mixed Ewing sarcoma (Fig. 4a [viii and ix]), whereas Ewing sarcoma patients with high PROM1 expression showed good prognosis (Supplementary Fig. S5e), as analyzed using the R2 platform.