Only 47% and 66% of the CD7 CpG sites tested are methylated in the CD7+ cells of CML1 and CML10 respectively, compared to 90% (CML1) and 83% (CML10) in the CD7- cells (P < 0.0001) suggesting that hypomethylation of the CD7 promoter is associated with higher expression of CD7 on individual cells in CML patients. This evidence concerns the gene CD7 and chronic myelogenous leukemia, BCR-ABL1 positive.