Other studies indicated the intron1 of NOTCH3 as an enhancer region devoid of repressive H3 tri-methylated lysine 27 mark (H3K27me3) and associated with the active chromatin mark histone H3 acetylated lysine 27 (H3K27ac) in T-ALL cells, This gene region appears to be required for Notch1-dependent transcriptional activation of NOTCH3 (14, 15). This evidence concerns the gene NOTCH1 and acute lymphoblastic leukemia.