They observed a significant increase in serum MMP-9 levels in patients with metastases and concluded that serum MMP-9 is a better marker than serum MMP-2 for predicting the development and progression of breast cancer.(31) Additionally, other authors in India reported higher mRNA expression levels of MMP-9 and vascular endothelial growth factor (VEGF-C) in breast cancer biopsy specimens compared to benign breast disease. This evidence concerns the gene MMP9 and breast fibrocystic disease.