In this study, we established an gefitinib resistant lung adenocarcinoma cell line (i.e. PC9/GR) from lung adenocarcinoma PC9 cell line which was sensitive to gefitinib. Then microarray was performed to elucidate the lncRNAs, cirRNAs and mRNAs involved in gefitinib resistance. Overall design: gefitinib resistant PC9/GR cells with three replications; gefitinib-sensitive PC9 cells with three replications