Furthermore, in the CML cell line KBM5, as well as IM-resistant CML cells KBM5 bearing T315I mutations, chidamide in conjunction with imatinib induced synergistic fatality, with a significant decrease in kinase activity of BCR-ABL and expression of acetyl-histone H3. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.