Previous studied revealed that HHLA2 was highly expressed in lung cancer,8, 38 more clinical samples of NSCLC patients should be used to validate our results. HHLA2 is expressed in primates but absent in rodents,9, 13, 40 it is necessary to find a suitable animal model to perform further researches. The gene discussed is HHLA2; the disease is non-small cell lung carcinoma.