STAT3 and malignant colon neoplasm: It is interesting to note that knockdown of CDK8 in colon cancer cell lines HCT116, LOVO, and SW480 does not appear to affect E2F1 protein levels, but does affect E2F1 transcriptional activity [33].We have also demonstrated that the decrease in cell viability of MDA-MB-468 cells treated with inhibitor 4 is dependent on the induction of STAT3 phosphorylation, and this effect is not observed in the two colon cancer cell lines used in this study.