Unsupervised HC algorithm confirmed that the 3,179 DEGs and the 537 DEGs signatures were able to correctly distinguish MSCs from other closely related fusion sarcomas, and to distinguish CDSs from EWSR1-NFATc2, Ewing sarcoma, MSS, MLS, and ARMS (Supplementary Figs. S3 and S4). This evidence concerns the gene EWSR1 and Ewing sarcoma.