In another study in NSCLC, TREM-1 expression was shown to be induced in TAMs by tumour cell mediated prostaglandine-2 (PGE2) production, suggesting a link between the tumour cell derived cyclo-oxygenase 2 (COX-2) pathway and the expression of TREM-1 in TAMs58. Here, PTGS2 is linked to non-small cell lung carcinoma.