Abstract: ObjectiveTo investigate the expression and significance of Elafin in lung cancer by database through
database data. MethodsElafin gene expression in lung cancer was analyzed by Oncomine database and verified by realtime fluorescence quantitative PCR (qPCR) in lung cancer tissues. Kaplan-Meier database was used to analyze the
relationship between Elafin expression and the prognosis of lung cancer patients. The correlated genes of Ealfin were
obtained from Linkedomics database. GO and KEGG analysis and protein-protein interaction network were analyzed by
GSEA tools and string databases, respectively. Results Compared with normal tissue, the mRNA level of Elafin was
significantly higher in lung cancer. Survival analysis showed that disease-free survival and overall survival were significantly
decreased in patients with high expression of Elafin. Linkedomics database showed that there were 7 697 correlated genes in
Elafin. GO and KEGG analysis showed that Elafin and correlated genes may related to humoral immune response,
granulocyte activation, IL-17 pathway and NF-κB pathway. The Elafin protein PPI network showed that Elafin may interact
with LOR, CSTA and FLG. Conclusion The high expressed Elafin in lung cancer tissues is associated with the prognosis of
lung cancer patients, which may be used as a potential target for diagnosis and treatment of lung cancer.

Key words: lung neoplasms, Elafin, data mining, prognosis