MMPs are investigated for their remodeling effects on embryogenesis, angiogenesis, tumor invasion, metastasis, and atherosclerotic processes.22,23 MMP2 (gelatinases A) polymorphism was identified as increased in murine tumors in 1981 by Liotta et al.24 This molecule is responsible from destruction of gelatine, fibronectin, and collagen types IV, V, VII, and X. We have studied the MMP2 gene −735 C > T polymorphism in PV, SP, and ET. This evidence concerns the gene FN1 and neoplasm.