MMP9 and neoplasm: As with the plasma levels, the tumor-free intestinal tissue extract MMP-9 levels remained similar after 12 years of cryopreservation with a median concentration of 8.1 ng/mL (17.7), range 2.8–34.6 ng/mL, correlating well with baseline levels [ρ = 0.97 (p < 0.01)], see Fig. 1.