Specific knockdown of FGFR1 by siRNA suppressed brachyury expression and epithelial–mesenchymal transition (EMT) (upregulation of E-cadherin and β-catenin and downregulation of Snail and fibronectin), whereas forced overexpression of FGFR1 induced brachyury expression and promoted EMT in lung cancer cells. The gene discussed is SNAI1; the disease is lung cancer.