In CML cell lines, in contrast with BMCs, HOTAIR and DNMT1 expression were enhanced, and PTEN expression was decreased in CML cells (all P < 0.05), among which K562 cells showed the greatest difference while KCL-22 cells showed the minimum difference with BMCs (Fig. 2A–D). This evidence concerns the gene DNMT1 and chronic myelogenous leukemia, BCR-ABL1 positive.