NR2F2 and lung cancer: To further investigate the downstream mechanisms of LncRNA NR2F2‐AS in lung cancer cells, we also transfect A549 and SPC‐A‐1 cells with si‐BMI1 to compare the effects of si‐LncRNA NR2F2‐AS, miR‐320b mimic and si‐BMI1 among cell proliferation, invasion and apoptosis.