H₂O₂induces proliferation in hematopoietic cells. (A) Proliferation of MV4-11 cells treated with GOX for 48 hours in the absence or presence of catalase (determined by MTS assay; n = 6). The graph shows MTS reagent absorbance at 492 nm as a percentage of untreated control absorbance (normalized to 100%). (B) KG-1 cell proliferation measured as in (A). (C) Proliferation of primary AML blasts and normal human CD34⁺ cells treated with GOX in the absence of growth factors (n = 3). (D) The rate of GOX-derived H₂O₂ production in culture medium (determined by Amplex UltraRed) as a function of GOX concentration. (E) Cell cycle analysis of MV4-11 cells treated with vehicle control or 5 mU/mL GOX in the presence or absence of catalase (n = 5). Significance of difference was determined by the Mann-Whitney U test or the Kruskal-Wallis test followed by Dunn’s multiple comparison test. *P < .05, **P < .01, ***P < .001.