MMP9 and hyperinsulinism: MMP9 expression (FCNG, 0.1+ins = 0.69; FCNG, 1.0+ins = 0.50, p = 0.089) was further decreased when 1.0 mmol/L metformin was administered under the influence of hyperinsulinemia in a normal glucose environment, indicating a supportive anti-metastatic effect.