MKI67 and neoplasm: The combination of lenalidomide and 5FU significantly reduced the tumor Ki67 proliferative index (p = 0.0002, comparing all treatment groups by One Way Anova); the mean Ki67 expression was 10.6 ± 2.5 % in mice treated with drug combination, 32.4 ± 2.2 % in mice treated with vehicle control, 19.9 ± 1.6 % in mice treated with 5FU alone, 21.9 ± 4.2 % in mice treated with lenalidomide alone (Fig. 5a, b).