HCAR2 and colorectal carcinoma: Butyrate interacts with G protein-coupled receptor 109A (GPR109A), leading to the downregulation of anti-apoptotic proteins such as Bcl-2 and Bcl-xL, and cyclin D1 in CRC cells, while simultaneously upregulating apoptotic receptor signaling pathways, which enhances apoptosis in CRC cells.