Bone marrow characteristics of TET2-engineered CH macaques. BM CD34⁺ HSPCs obtained at 12 (ZL26 and ZH63) and 30 months (ZL39) posttransplantation were plated for CFU assays. Colonies were isolated individually on day 14 for analysis. (A) Total CFU potential and composition of erythroid and myeloid colonies are plotted. (B) WT, uniallelic (UA), and biallelic (BA) edits for each target site in individual CFUs were identified by deep sequencing. (C) Targeted deep sequencing was performed on BM granulocytes and purified CD34⁺ HSPCs from ZL26 at 6.5, 12, and 39 months, ZL39 at 30 and 34 months, and ZH63 at 12 months posttransplantation. The percentage of reads containing indels at the TET2, DNMT3A, and ASXL1 target sites is indicated. (D) Serial sections of BM core obtained from ZL26 and ZH63 were stained with hematoxylin and eosin and myeloperoxidase antibody, along with animals receiving lentivirally transduced (ZK48) or non-CH edited cells (ZI35) as controls, with BM samples collected at similar time points posttransplantation. Representative microscopic images at 50× magnification are shown. (E) The number of nucleated cells per field in at least 5 different fields was quantified by Image J software. Data are presented as mean plus or minus standard error of the mean, and statistical significances were calculated by One-way ANOVA followed by Tukey’s multiple comparisons test, ∗P < .05; ∗∗P < .01; ∗∗∗P < .001.