The hypomethylation of the CD7 promoter region in CD34+CD7+ cells compared to CD34+CD7- cells of the CML-1 and CML-10 patient samples (Figure 5) denotes a likely physiological role for DNA methylation in the transcriptional repression of this gene. This evidence concerns the gene CD7 and chronic myelogenous leukemia, BCR-ABL1 positive.