Since, miR-140-5p was down-regulated and SIX1 was up-regulated in CML cells, and overexpression of miR-140-5p promoted CML cell apoptosis, we investigated whether miR-140-5p down-regulated SIX1, leading to cell apoptosis. This evidence concerns the gene SIX1 and chronic myelogenous leukemia, BCR-ABL1 positive.