In particular, the high expression of MMP-2 within the cyst fluid and the inner layer of the cyst wall would seem to be responsible for the tumor size enlargement and the marked adhesion of cystic VS to the nerve, also emphasizing the role that the proteolytic activity of MMP-2 may play on the integrity of the blood-liquid barrier at the nerve surface (39). Here, MMP2 is linked to neoplasm.