In CML, several studies have identified DNA methylation changes in the promoter of some genes in the advanced phases of the disease, for instance hypermethylation of the ABL1 [80], cell cycle-regulating genes [43], CEBPA [81], PU-1 [79], CALCA [82], HOXA4 or HOXA5 [63] gene promoters. The gene discussed is HOXA4; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.