In order to explore whether PTGS2 is involved in the chemoresistance of NSCLC, we first compared the expression levels of PTGS2 between the NSCLC cell line A549 and the corresponding cisplatin-resistant cell line A549/DDP, which displayed significant higher resistance to cisplatin (DDP), adriamycin (ADM), and gemcitabine (GEM) than A549 cells (Table S2). Here, PTGS2 is linked to non-small cell lung carcinoma.