**2.2 Invasion through matrix degradation**

One of the hallmarks of the malignancy is the disruption of basement membrane and enzymes extruded from tumor cells degrade matrix for invasion. These enzymes form a diverse family, including serine/cysteine proteinases, cathepsin, disintegrin, ADAM metalloproteinases, and matrix metalloproteinases (MMP). Increased MMPs are considered poor prognosis in several cancer types and correlate to invasion and metastasis. Cathepsins, proteinase inhibitors, and cysteine proteinase inhibitors regulate proteolysis. Both tumor and stromal cells play roles in the inhibitory mechanism [1, 5].
