Identification of DUX4-rearranged ALL by the differential expression profile of the DUX4 gene clusters and ERG exons. The plot shows read depth coverage on 3 different chromosomal regions, that is, DUX4 multifamily gene array in the telomeric regions of chromosomes 4 and 10, and ERG gene on chromosome 21 aligned on the human Hg19 genome. DUX4 gene is exclusively expressed in the DUX4-rearranged group, and is associated, in most cases (27 of 35), with expression of an alternative exon 6 of ERG (ERGalt). The location of the ERGalt exon is shown in red. Screenshot of the IGV browser. ∗Here, 2 cases grouped within the PAX5-driven group and 1 in the iAMP21 group has an outlier expression of CRLF2. AJ2E, group of ABL-, JAK2-, and EPOR-fusion cases.