Our current study demonstrate that TGF-β1 treatment may activate the canonical TGF-β1 signaling by the induction of phosphorylated smad2/smad3, while Smad7 inhibits such activation, which can enhance the EMT-associated invasive phenotypes of ESCC cells in vitro. The gene discussed is TGFB1; the disease is esophageal squamous cell carcinoma.