BCR and acute lymphoblastic leukemia: As miR-92a expression was unchanged between BCR-ABL-positive and -negative ALL cells (Figure 1), we transduced TonB cells to overexpress miR-17∼19b, a derivative of miR-17∼92 suitable for transgenic expression.21, 26 miRNA expression was increased between 5- and 16-fold upon transduction (miR-17 5.2-fold, miR-18a 2.1-fold, miR-19a 9-fold, miR-19b 10.6-fold, and miR-20a 15.8-fold).