Effect of anti–TGF-β on TGF-β and incidence of LPD. (A) Anti-TGF-β neutralizes TGF-β in vivo. The hu PBL-SCID mice were given injections of 125 μg anti–TGF-β antibody (A411) or PBS 3 times per week. Serum samples were tested at week 6 for the presence of TGF-β by ELISA. Data are shown as mean pg/mL TGF-β derived from triplicate determinations, 5 mice/group. Error bars indicate standard deviation. (B) Anti-TGF-β reduces incidence of LPD in a dose-dependent manner. The hu PBL-SCID mice were treated with 100 μg or 125 μg anti–TGF-β antibody A411 or mouse IgG 3 times per week for 9 weeks. At harvest, the presence of B-cell tumors was assessed visually and confirmed by flow cytometry. (ip indicates intraperitoneally.)