Given that several of the novel regions had epigenetic hallmarks of either promoter and enhancer activity, we analysed a panel of transient luciferase reporter constructs in K562 (erthyroid/SCL +) and HPB-ALL (lymphoid/SCL -) to ask whether these novel sequences could enhance or drive gene expression in vivo and whether their effects were lineage-specific or specific to SCL regulation. This evidence concerns the gene TAL1 and acute lymphoblastic leukemia.