Tsg interacts with TGF-β. Purified Tsg-V5 or B7-H3-V5 and TGF-β were incubated overnight at 4°C, and subsequently immunoprecipitation was done with V5-specific antibody coupled on protein G. Complexes (lanes 1-2) were analyzed by SDS-PAGE along with purified proteins (lanes 3-4) and immunoblot was conducted using TGF-β-specific mAb or V5-specific antibody. Incubation of purified Tsg-V5 or B7-H3-V5 with diluent alone was used as control (indicated as −).