CD3E and Splenomegaly: Consistent with previous reports on OKT3-induced capillary leakage in humans [20,21,22,23,24,25], mitogenic W-CD3e-mAb-treated mice showed a significant increase in tissue-infiltrated (IVS−) PMNs in both the spleen and lungs (* p < 0.05; Figure 3C) and a significant increase in W/N ratios (** p < 0.01; Figure 3D) in the spleen, consistent with the significant splenomegaly observed in these mice (shown in Figure 2B).