DUX4 and precursor B-cell acute lymphoblastic leukemia: Using published RNA-seq data generated from 32 B-ALL patient samples that harboring IGH-DUX4 translocation and human embryos9,13,17, we found that DUX4 expression is much higher compared with normal expression in human cleavage stage embryos (the median FPKM [fragments per kilobase of transcript, per million mapped reads] 145.4 vs. 6.65, Fig. 1a).