MMP9 and neoplasm: Metalloproteinases (MMPs) are a family of endopeptidases participating in the degradation of extra cellular matrix and basement membrane barriers.5, 6, 7 Some members of the MMPs family have been shown to promote tumor growth, angiogenesis, invasion and metastasis in cancer patients.8, 9, 10 Matrix metallopeptidase 9 (MMP-9) is a collagenase responsible for the degradation of type IV collagen, the major component of the basement membrane, and others essential extra cellular matrix component̀s, being involved in the tumor cell invasion and metastasis.11, 12