The level of phosphorylated Smad2 (P-Smad2) and total Smad2 (Smad2) was assessed by immunoblotting and β-actin was used as a loading control. Lower bar graphs show WB quantification of P-Smad2 (P-S2) normalized to β-actin. (E) 1603MED cells were transfected with the indicated control siRNA (siCTRL, blue) or targeting INHBB (siINHBB, red). Lysates were prepared 48 hours after transfection. Lower bar graphs represent the quantification of the relative level of P-Smad2 (P-S2) to β-actin. The p-values were determined by unpaired t-test. *p < 0.05, **p < 0.01, ***p < 0.001. Bars represent the mean ± SD. Number of replicates is n≥3. 