TADF cells were treated with vehicle, TGF-β1 (1ng/ml), or the combination of TGF-β1 and PTX (TGF-β1 followed by PTX, or PTX followed by TGF-β1) for 24 hr. A. Western blot of pSmad1/5, Samd1/5, pSmad2, and Smad2, in TADF cells. All TGF-β1 treatments increased phosphorylation of both Smad 1/5 and Smad2 ( # P<0.01). B. Phosphorylation level of Smad1/5 in TADF. Pretreatment with PTX significantly decreased the phosphorylation level of Smad1/5 (*P<0.01). C. Phosphorylation level of Smad2 in TADF Pretreatment with PTX did not affect the phosphorylation level of Smad2 (#p>0.05).