STAT3 and colorectal carcinoma: The authors further demonstrated that siRNA- and shRNA-mediated silencing of STAT3, as well as treatment with the small-molecule inhibitor STATTIC, which blocks STAT3 phosphorylation, significantly decreased clonogenic survival of CRC cell lines following exposure to 3 μM of 5-FU and irradiation in a dose-dependent manner, with dose-modifying factors (DMF) of 1.3 to 2.5 at a surviving fraction of 0.37 [62].