Unsupervised hierarchical clustering using RNA-seq data revealed similarities between the transcriptomes of ITD-positive CCSKs and BCOR–CCNB3 fusion-positive UDS and suggested that RNA-expression programs in these tumours are distinct from those of Wilms tumours, other sarcomas or the single ITD-negative CCSK tested (Fig. 3a). The gene discussed is BCOR; the disease is sarcoma.