The Glucagon Receptor (GCGR) is a member of the G protein-coupled receptor family, characterized by a seven-transmembrane domain structure and a cytoplasmic C-terminus. GCGR is primarily located on liver cells and pancreatic α cells, serving as a receptor for glucose and its breakdown products. Activation of GCGR leads to the production of cAMP, which in turn activates the protein kinase A (PKA) signaling pathway, promoting glycogen breakdown and glucose synthesis. The gene expression of GCGR is regulated by various factors, and its tissue-specific expression and mutations are associated with the development of diseases such as diabetes.