To explore the underlying mechanism by which miR-144-5p enhances the effects of IR in lung cancer cells, we searched for the targets of miR-144-5p with the help of TargetScan, an online database (http://www.targetscan.org/) and found that 2078 transcripts including ATF2 mRNA contain miR-144-5p seed sequences. The gene discussed is ATF2; the disease is lung carcinoma.