let-7a/f inhibition increases HBG expression in xenografted human primary erythroid cells. (A) Schematic of NBSGW xenograft experiments using transduced primary human CD34⁺ cells. Transduced GFP⁺ hCD235⁺ erythroid cells were purified from mouse BM for analysis. All data are shown as mean ± SD with individual data points, n = 5 for controls and 6 for let-7a/f decoy. ∗P < .05; ∗∗P < .01; ∗∗∗∗P < .0001 by the Student t test. (B) Engraftment analysis measured at 4 months, calculated as human percentage of CD45⁺ cells. (C) The expression levels of let-7a-5p and let-7f-5p measured by miRNA qRT-PCR upon let-7a/f inhibition. Results are normalized to miRNAs miR-16/103a/191. (D) Real-time RT-PCR of BCL11A mature mRNA and primary transcript in xenografted early-stage erythroid precursors. (E) Real-time RT-PCR of β-globin-like genes in BM CD235ab⁺ human primary erythroid cells from NBSGW xenografts. (F) ddRT-PCR quantification of HBG transcripts as percentage of total β-like transcripts. BM, bone marrow.