Western immunoblotting shows absence of phosphorylated Smad2 in TGF-βRII-Δcyt–transduced CTLs with addition of TGF-β.

Nontransduced, eGFP-transduced, and TGF-βRII-Δcyt–transduced CTLs were incubated for 1 hour with 5 ng/mL TGF-β, as indicated. The presence or absence of Smad2 (S2) and phosphorylated Smad2 (P-S2) was detected by Western immunoblotting by using anti-Smad2 and antiphospho-Smad2 antibodies, respectively.