UM171 enhances reconstitution of CD34⁺ cells expressing a BCL11A shmiR in NBSGW mice. (A) Outline of competitive assay, CD34⁺ cells from patients with SCD (n = 3) were prestimulated and transduced in the presence or absence of UM171 with a Venus- or a BFP-expressing vector. Equal numbers of Venus-marked and BFP-marked cells were mixed 1:1 and coinjected into NBSGW mice. (B) Competitive repopulation between cells transduced in presence or absence of UM171. Both vectors expressed the BCL11A shmiR. (C) Ratio of engrafted gene-marked cells after transduction in the presence or absence of UM171. Data represent mean ± SD, n = 9, each data point represents an individual mouse. ∗P < .05; ∗∗∗∗P < .0001.