RBM12 depletion in CD34⁺HSPCs derived from patients with SCD. CD34⁺ HSPCs isolated from apheresis waste product of 3 patients with SCD targeted with 2 independent RBM12 sgRNAs along with an NT control. (A) Western blot analysis with indicated antibodies at day 10 of differentiation. (B) HbF induction assayed via qRT-PCR and high-performance liquid chromatography. Plotted are means ± standard deviation (n = 3). ∗P < .05 by Student’s t test. Left: qRT-PCR of HBG1/2 mRNA as percentage of total β-like globin transcripts at day 12 of differentiation. Results are normalized to HPRT1. Right: High-performance liquid chromatography at day 15 of differentiation. (C) Left: Representative images of sickling assay results. Sickled cells are indicated by yellow arrows. Original magnification ×40 on an Olympus BX40 microscope fitted with an Infinity Lite B camera (Olympus) and the coupled image capture software. Right: Quantification of percent sickled cells. Each dot represents a distinct field of view. Each sample has approximately 1000 total cells quantified. ∗∗∗∗P < .0001 by Student’s t test.