D458 cell lines were treated with PBS (vehicle, black) or with ActivinB (green). Immunoblot of phosphorylated Smad2 (P-Smad2), total Smad2 and β-actin in response to ActivinB stimulation for 24 hours. Quantification of P-Smad2 (P-S2) to β-actin are shown on right panels. Bars represent the mean ± SD. Number of replicates is n≥3. 