CREB‐1 reduced TGF‐β1‐stimulated expression of collagen I, activated Smad2/3 and upregulated expression of Smad7. In addition, activated CREB‐1 attenuated the activation of extracellular signal‐regulated kinase 1/2 induced by TGF‐β1, expression of Ras homolog gene family, member A (RhoA) and Rho‐ass