FOXO1 is upregulated in AE leukemia and preleukemia cells. (A) Microarray analysis of FOXO1 transcript levels in t(8;21)-positive compared with t(8;21)-negative AML patient samples from Ross et al.²²  (B) Immunoblot showing FOXO1 protein levels in t(8;21) and cytogenetically normal [non-t(8;21)] AML patient samples. FOXO1 mRNA levels determined by quantitative PCR (qPCR) (C; n = 4, error bars represent standard deviation [SD]) and protein levels (D) in AE- or empty vector (MIT)–transduced CD34⁺ HSPCs. Cellular fractionation immunoblot (E) and immunofluorescence analysis (F) to determine the subcellular localization of FOXO1 in AE cells. The images were obtained by Leica DMI6000 fluorescent microscope with ×40 objective. Bar represents 20 μm. All P values were calculated by unpaired 2-tailed Student t test.