Target genes of the B cell transcription factor, STAT5, activation of which is known to co-operate with haploinsufficiency of PAX5 and EBF1 in initiating ALL (Heltemes-Harris et al., 2011), were markedly upregulated in ETV6-RUNX1 proB cells, as shown by GSEA (Figure 6C). This evidence concerns the gene EBF1 and acute lymphoblastic leukemia.