MMP2 and neoplasm: More recently, many authors reported NPs functionalized with Matrix Metalloproteinase 2 (MMP2), an extracellular enzyme upregulated and produced by cancer cells and various tumor stromal cells in the tumor microenvironment, involved in cancer initiation, growth and metastasis; in addition, MMP2 binds to cancer and endothelial cells to facilitate cancer invasion and angiogenesis [129].