GFI1 and acute myeloid leukemia: Cheng et al. discovered that relapsed AML patients displayed higher HO-1 levels, which were associated with the upregulation of histone deacetylases (HDAC1, HDAC2, and HDAC3) and inversely correlated with the expression of Growth Factor Independent-1 (GFI-1), a transcriptional repressor known to inhibit various malignancies.