RsTβRII-IFN-γ fusion protein blocks the inhibitory effect of TGF-β1 on CCL-64 cell proliferation. Serial dilutions of RsTβRII-IFN-γ fusion protein were incubated with 800 pg/ml TGF-β1 for one hour in assay medium in a 96-well plate. 1 × 104 cells of CCL-64 per well were added into each well. The cells were incubated at 37°C for 72 hours and 10 μl MTT (5 mg/ml) were added into each well 4 hours before the end of the culture. The cells were lysed in 150 μl DMSO. The absorbance at 540 nm was measured. Each assay was carried out in triplicate. Mv1Lu: Untreated CCL-64 cells. 1: Original purified RsTβRII-IFN-γ fusion protein; 2~6: 2 × serial dilutions of 1; TGF-β1: CCL-64 cells treated with TGF-β1 without RsTβRII-IFN-γ fusion protein.