PCNA staining of CRC cells growing in the liver (A) shows that CGP42112A treatment inhibited MoCR proliferation in vivo. Immunostaining for active caspase 3 also confirmed a treatment-induced increase in cancer cell apoptosis (B) in the same in vivo model. MoCR metastases were induced in the liver of CBA mice and allowed to grow for 21 days before fixing in PFA and immunohistochemcial analyses. Significant P values are shown with an * and solid line, while those of interest with P values between 0.1 and 0.05 are indicated with a dotted line and no *. Data are presented as mean ± S.E.M.