Studies in mice and cultured cells have shown that COX-2 has an important role in the induction and development of cancers, and COX-2 is upregulated in lung cancer and correlates with tumor angiogenesis and apoptosis.38,39 Furthermore, COX-2 overexpression can reduce host immunity and regulate cell adhesion to enhance tumor invasion and metastasis.40,41 Therefore, COX-2 is considered a target, and the reversal of its effects on tumor multidrug resistance via the COX signaling pathway is mediated by inhibiting COX-2 in cancer cells. This evidence concerns the gene PTGS2 and cancer.