Depletion of T cells via the CD3×CD3 BsAb is not associated with clinical side effects. Mice were treated as in Figure 3 and were weighed weekly (A). At different time points, blood was taken and stained for the presence of human cells. The number of human CD4 (B) and CD8 (C) T cells was determined using flow cytometry. n = 5 mice per group. Experiment was repeated 2 times.