Consistent with our observation in IGH-DUX4 B-ALL patient samples, DUX4 expression in Nalm6 is much higher compared with its normal expression in human cleavage stage embryos (FPKM 41.3 vs. 6.65, Fig. 1a) and much lower than Igμ (FPKM 41.3 vs. 638.2, Fig. 1b), making the cell line a good model for evaluating allele specificity of the IGH-DUX4 translocation. Here, CD40LG is linked to acute lymphoblastic leukemia.