We asked whether the GATA-1 mediated repression involves any of the established chromatin marks, such as H3K9Me3, H3K27Me3 (marks of repressed chromatin) and also H3K9Ac at the PU. 1 gene locus in AML-ELs (OCI-M2,K562) and the control cell lines (SKM1,HeLa), all transfected with pXMGATA-1. This evidence concerns the gene GATA1 and acute myeloid leukemia.