TGFB1 and colon carcinoma: Western blotting showed that protein levels of the immunosuppressive cytokine TGF-β1 were decreased both in MC38 murine colon carcinoma cells and LOVO human colon carcinoma cells after stimulated by C. difficile TcdB with concentration of 0.1 ng/mL, 0.2 ng/mL, 0.4 ng/mL, or 0.8 ng/mL, respectively (Fig. 2B).