Because CRC factors have high and specific expression in their corresponding cell types, we interrogated the Cancer Cell Line Encyclopedia (CCLE) dataset and noted that, compared with other five CRC candidates (NFATC2, FOS, IRF2, ZBTB7B and MEF2D, Supplementary Figure S1), the expression of 4 candidate TFs (KLF15, NKX2-2, TCF4 and RREB1) showed restricted expression pattern in Ewing sarcoma cell lines (defined as top 5 among all cell types, Figure 1B). This evidence concerns the gene TCF4 and Ewing sarcoma.