In previous studies, COX-2 was found to be involved in cancer tumor cell metastasis by regulating biochemical changes, including altering matrix metalloproteinase (MMP)-2, MMP-9, and epithelial–mesenchymal transition (EMT) marker expression and increasing tumor cell adhesion to extracellular matrix (ECM) proteins and endothelial cells [22–24]. The gene discussed is MMP9; the disease is neoplasm.