The results showed that STAT3 decoy ODN significantly decreased viable cell number by inducing apoptosis and reducing [3H]-thymidine incorporation of A549 non-small-cell lung cancer cell line in vitro (Fig. 2), which was in parallel with our recent findings in a different type of lung cancer cell line PG [29], suggesting that STAT3 decoy could effectively suppress cell growth of lung cancer. Here, STAT3 is linked to lung cancer.