In fact, gemfibrozil and clofibrate rather down-regulated Mt1 and Mt2 genes [19]; 4/the same holds true in human hepatoma cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin, in which the only gene differentially expressed among those up-regulated in our mice liver was CoxI. However, it was 2.4-times down-regulated in this cell type [21]. The gene discussed is MT-CO1; the disease is hepatocellular carcinoma.