Rapid activation of BCR-mediated signaling in the presence of H₂O₂ is a common feature of FL sample B cells and differs from normal PBMC B cells. Differences in initiation of BCR-mediated signaling were compared in 5 tumor biopsy samples from individuals with FL and 5 PBMC samples from healthy donors. Samples were stimulated for 4 minutes by a combination of BCR cross-linking and H₂O₂ (α-μ/γ + H₂O₂) or left unstimulated. The average MFI of each phosphoprotein in CD20⁺ B cells has been graphed. Error bars indicate standard deviation.