C-terminal binding proteins (CTBPs) are conserved transcriptional repressors important in cancer and inflammation. Uniquely amongst transcriptional co-regulators, CTBPs possess a functional dehydrogenase domain. Since multiple malignancies display elevated CTBP levels, CTBP inhibitors targeting this dehydrogenase domain have been developed. While the importance of CTBPs dehydrogenase function for transcriptional regulation remains unclear, several studies have relied on CTBP inhibitors.