RsTβRII blocks the growth-inhibitory effect of TGFβ1 on CCL-64 cells. Serial dilutions of RsTβRII 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 and the absorbance at 540 nm was measured and ratios of inhibition were calculated. Mv1Lu: Untreated CCL-64 cells; 1: Original purified RsTβR protein; TGF-β1: CCL-64 cells treated with TGF-β1 but without RsTβRII protein.