To investigate the role of SOX9 played in NSCLC metastasis, we transduced A549 and NCI-H460 NSCLC cells with a pSin/SOX9-derived retroviral construct to establish stable SOX9-over-expressing cell lines (Fig. 2a) or pSuper/SOX9 shRNA-derived retroviral construct to establish SOX9-knock down cell lines (Fig. 2b). The gene discussed is SOX9; the disease is non-small cell lung carcinoma.