Inhibition of ROS elevation protects the human HSPCs from functional deterioration in an in vivo RIBE model. (A) Experimental diagram of in vivo antioxidant treatment RIBE model. NOG mice were given antioxidants for 7 days before irradiation. All of the following procedures were consistent with those shown in Figure 1A (n = 4-7 per group). (B) Mean human cell engraftment (top) and bars represent the fold difference of engraftment levels between each group (bottom). (C-D) Frequency of human CD34⁺CD38⁻ (C) and CD34⁺CD38⁺ (D) cells in the BM of recipient. (E) Mean engraftment level of human cells in the spleen of recipients. (F) Number of hematopoietic clones formed by human CD34⁺ cells of each group (*P < .05; **P < .01; ***P < .001).