MMP9 and type 2 diabetes mellitus: In contrast MMP9 gene expression was significantly increased by TNF-α at both 2.5 and 25 ng/ml, and in both ND-DF and T2DM-DF to a comparable degree (P < 0.0001 for effect of TNF-α, two-way ANOVA, n = 5 ND-DF and n = 4 T2DM-DF; Fig. 4d).