Gfi1 is a master regulator of microRNA expression. (A) MicroRNA microarray profile of total BM cells from both C57Bl/6 and Balb/c Gfi1+/+ and Gfi1−/− littermates. (B) Quantitative real-time (TaqMan) miR analysis of RNA from panel A and Lin− BM cells. (C) TaqMan analyses of steady-state miR expression in Gfi1−/− Lin− BM cells transduced with MSCV empty vector or MSCV encoding Gfi1. (D) TaqMan analyses of miR expression in HL60 cells transduced with Gfi1-targeting lentiviral shRNA (65 and 68) and nontargeting control (NT). Immunoblot showing Gfi1 knockdown (inset). (E) TaqMan analyses of microRNA in human CD34+ bone marrow cells from healthy donors (n = 3) versus GFI1N382S mutant patient. TaqMan results are represented as means ± SD from at least 3 independent experiments.