Knockdown of FOXL2 in NSCLC significantly decreased TGF‐β receptor I, TGF‐β receptor II, Snail, p‐Smad3, N‐cadherin, MMP2, MMP9, and Vimentin levels and markedly increased E‐cadherin expression, and the metastatic ability of NSCLC cells was reduced. The gene discussed is SMAD3; the disease is non-small cell lung carcinoma.