A, Intertumoral heterogeneity of soft-tissue and bone tumors as assessed by DNA methylation array. Unsupervised, nonlinear t-distributed stochastic neighbor embedding projection of methylation array profiles of 610 soft-tissue and bone tumor samples. Samples have been selected from a large database of sarcoma datasets to serve as reference profiles for training a supervised classification model based on strict criteria. B–G, Undifferentiated small round cell sarcomas of bone and soft tissue. B, Ewing sarcoma with EWSR::FLI 1 fusions. C, Soft-tissue sarcoma with BCOR alteration (BCOR::MAML3 fusion). D, CIC::DUX4 sarcoma. CD99 membranous staining varies from strong and diffuse in ES (E) and BCOR::MAML (F) to focal in CIC::DUX4 (G).