SP1 and lung carcinoma: Overexpression of GFP-Sp1 decreased the migration ability of lung cancer cells, and knockdown of Sp1 increased the migration ability of A549 and E2-A549 lung cancer cells in wound healing (Fig. 5A and Additional file 2: Fig. S1) and chamber migration assays (Fig. 5B), suggesting that Sp1 negatively regulates the migratory ability of lung cancer cells.