Besides, Geng et al. (2021) discovered that butyric acid, in addition to acting as a histone deacetylase inhibitor and activating the G protein-coupled receptor GPR109a, not only significantly inhibited glucose transport and glycolysis in CRC cells by reducing the contents of glucose transporter 1 in the cell membrane and glucose-6-phosphate dehydrogenase in the cytoplasm but also dramatically improved the chemotherapeutic effect of 5-FU on tumor cells. This evidence concerns the gene HCAR2 and colorectal carcinoma.