MiR-130b and miR-128a promote the B-lymphoid bias of FL Mll-AF4⁺ preleukemic cells. (A) Expression of miR-130b and miR-128a in E14 FL HSCs/MPPs and LMPPs from Mll-AF4- VEC-Cre⁺ and Mll-AF4⁺ VEC-Cre⁺ embryos. (B) ATAC-Seq of mouse E14.5 FL LMPPs (WT and Mll-AF4⁺ VEC-Cre⁺). Each trace represents a pool of 4 biological replicates. The gray box highlights the promoter that regulates each miRNA. Arrows indicate an open chromatin region. (C) Expression of miR-130b or (D) miR-128a in transduced FL Mll-AF4⁺ LSK. (C) Expression of miR-130b or (D) miR-128a in transduced FL Mll-AF4⁺ LSK. (E) Experimental approach for the lentiviral transduction of FL Mll-AF4⁺ LSK and functional validation. Transduced cells were monitored with GFP expression. Clonogenic potential of transduced LSK in (F) myeloid and (G) B-lymphoid conditions. (H) Proliferation of myeloid and lymphoid cells in colony-forming assays. Data were compared using a Mann-Whitney U test: *P < .05; **P < .01; ***P < .001; ****P < .0001. Experiments were conducted in triplicate or more. Graphs are presented as mean ± standard error of the mean. CFU-C, colony-forming unit cell.