High levels of miR-17-5p, which further downregulate CDKN1A (Cyclin Dependent Kinase Inhibitor 1A), p21 and E2F1 tumor suppressor genes in imatinib sensitive and resistant chronic myeloid leukemia (CML) cells compared to peripheral blood mononuclear cells (PBMCs), have also been observed [111]. This evidence concerns the gene E2F1 and chronic myelogenous leukemia, BCR-ABL1 positive.