In addition to the induction of apoptosis, UA has also been reported to prevent the metastasis of cancer through down-expression of matrix metalloproteinases (MMP-2 and MMP-9) [12, 34] relating to the microenvironment of cancer cells; these enzymes were detected in E. granulosus hydatid cyst fluid, cyst membranes and protoscolices, and are involved in pathology-related tissue remodeling [35, 36]. This evidence concerns the gene MMP9 and cyst.