The RNA-seq data analysis shows that AT-1 and sister cell line AT-2, obtained from a 5 year old boy with pre-B ALL at 1st and 2nd relapse [21], also express the ETV6 exon 5/RUNX1 exon 4 fusion (Table 1, Figure 1, Supplementary Figure S1A). This evidence concerns the gene RUNX1 and acute lymphoblastic leukemia.