Based on the paradigm that TcdC is a major suppressor of toxin production we expected precocious and significantly elevated transcription levels of tcdA, tcdB, tcdE and tcdR in the CT::tcdC strains compared to wild type. However, our data indicate that TcdC exerts a moderate, if any, effect on the transcriptional levels of the PaLoc genes and the expression of toxins in C. difficile 630Derm under the conditions tested.