Here FC decreased histone deacetylase 1 (HDAC1) and HDAC2, and induced acetylation of H3K9, H3K18, and H4K8 in K562 and KBM5 cells, implying the critical role of HDAC inhibition in FC induced apoptosis in CML cells. Here, HDAC9 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.