STAT3 and lung carcinoma: To investigate whether CDK1 and STAT3 are essential for iron-mediated colony formation in lung cancer cell lines, we cultured lung cancer cells in low-adherent 96-well plates with RPMI 1640 supplemented with 0 or 100 μM FS, and treated the cells with CDK1-selective inhibitor RO-3306 (CDK1i, 10 μM) and STAT3-selective inhibitor Stattic (5 μM) for 12 days.