Figure 3.

The increased tumor mass after genetic ablation of Furin in the liver can be explained by a decreased apoptosis and/or an increased proliferation of the hepatocytes. (a) The apoptosis index in the liver tumors of Furin knockout mice was similar to that of wild type littermates at every time point investigated. (b) The hepatocyte proliferation index was significantly increased in the liver tumors of 5-week-old Furin knockout mice as compared to those in the liver tumors of littermate Furin wild type mice. This difference could not be observed in older mice. Increased proliferation is thus at least one of the mechanisms that can explain the increased tumor mass after genetic ablation of Furin in the liver tumors. Student's t-test was used to determine statistical significance (n = 3-4).