ChIP-chip analysis of human hematopoietic stem/progenitor cells transduced with the AML1-ETO fusion gene enabled us to identify 1168 AML1-ETO target genes, 103 of which were co-occupied by histone deacetylase 1 (HDAC1) and had lost the hyperacetylation mark at histone H4, and 264 showed a K9 trimethylation at histone H3.     ///    "Furthermore, AML1-ETO target genes had a significant correlation between the chromatin marks studied and transcriptional silencing. "    ///    "Therefore, this study provides a global analysis of AML1-ETO functional chromatin modifications and identifies the important role of Sp1 in the DNA binding pattern of AML1-ETO, suggesting a role for Sp1-targeted therapy in this leukemia subtype.. "    ///    "Interestingly, AML1 binding sites were absent on a large number of selected AML1-ETO promoters and an Sp1 binding site was found in over 50% of them. "    ///    " The AML1-ETO fusion protein, which is present in 10-15% of cases of acute myeloid leukemia, is known to repress myeloid differentiation genes through DNA binding and recruitment of chromatin-modifying proteins and transcription factors in target genes. "    ///    Chromatin modifications induced by the AML1-ETO fusion protein reversibly silence its genomic targets through AML1 and Sp1 binding motifs.. 