Redox sensitivity of leukemic and HD B cells. Samples were thawed and rested for 24 hours before modulation with 3.3 mM H₂O₂ for 10 minutes, or left unmodulated. (A) Representative flow cytometry histograms of BCR phosphoproteins in basal conditions (unmodulated) or after H₂O₂ modulation in B cells from HDs (n = 9) and patients with CLL (n = 42), compared with autofluorescence signals. (B) Unmodulated levels of signaling protein phosphorylation in B cells from HDs and patients with CLL. Protein phosphorylation was measured as log2 of relative median fluorescence intensity (log2-fold autofluorescence). The table indicates values of variance (σ²) for each phosphoprotein among HD and CLL samples. (C) Signals of phosphoproteins (log2-fold autofluorescence) in the unmodulated condition and after H₂O₂ modulation in B cells from HDs (left) and patients with CLL (right). (D) Comparison of response to H₂O₂ modulation, measured as the log2-fold change in phosphorylation between H₂O₂-modulated and unmodulated conditions, between B cells from HDs and patients with CLL. (E) Responses of pSYK, pERK1/2, and pp38 to H₂O₂ modulation, measured as log2-fold change, in the absence or presence of 5 mM NAC (n = 24). Lines indicate mean value. Comparisons were performed using the Student t test. *P ≤ .05; **P ≤ .01; ***P ≤ .001. (F) Representative contour plots of pSYK, pERK1/2, and pp38 in basal conditions (unmodulated) or after H₂O₂ modulation in B cells from HDs and patients with CLL.