Unlike in earlier studies of lung and breast cancers [31–33], the results of the present study imply that GC cells may spontaneously acquire mesenchymal-like features induced by autocrine TGF-β1-driven constitutive activation of SMAD2, which is consistent with previous studies of human hepatocellular carcinoma cells [34, 35]. Here, SMAD2 is linked to hepatocellular carcinoma.