PTGS2 and non-small cell lung carcinoma: However, the mechanism of TAMs in NSCLC progression remains unclear, so this study aimed to investigate the role of TAMs in NSCLC progression and to find potential therapeutic targets.<h4>Methods</h4>Gene Expression Profiling Interactive Analysis (GEPIA) database was used to analyze the expression of prostaglandin E2 receptor 4 (EP4) mRNA in NSCLC and normal lung tissues; the protein expression levels of cyclooxygenase-2 (COX-2), EP4, cluster of differentiation 86 (CD86), CD163 and CD31 were detected by immunohistochemistry (IHC) in 120 NSCLC tissues and 24 paracancerous tissues specimens.