The selective COX-2 inhibitor celecoxib has been previously reported to inhibit lung and lymph node metastasis in a colon cancer xenograft, and COX-2 inhibition by celecoxib has been observed to decrease angiogenesis, vascular endothelial growth factor expression levels and prostaglandin E2 production (41). Here, PTGS2 is linked to metastatic malignant neoplasm in the lymph nodes.