The function of Ensembl gene identifier ENSG00000115263 (GCG, glucagon) is as follows. [Glucagon]: Plays a key role in glucose metabolism and homeostasis. Regulates blood glucose by increasing gluconeogenesis and decreasing glycolysis. A counterregulatory hormone of insulin, raises plasma glucose levels in response to insulin-induced hypoglycemia. Plays an important role in initiating and maintaining hyperglycemic conditions in diabetes. Binds to and activates the glucagon receptor GCGR, which couples to the G(s) G protein and elevates intracellular cAMP, triggering downstream metabolic responses (PubMed:32193322). {ECO:0000269|PubMed:32193322, ECO:0000303|PubMed:10605628, ECO:0000303|PubMed:12626323}. [Glucagon-like peptide 1]: Potent stimulator of glucose- dependent insulin release (PubMed:22037645, PubMed:40446798). Also stimulates insulin release in response to IL6 (PubMed:22037645). Plays important roles on gastric motility and the suppression of plasma glucagon levels (PubMed:10605628, PubMed:14719035, PubMed:12554744). May be involved in the suppression of satiety and stimulation of glucose disposal in peripheral tissues, independent of the actions of insulin (PubMed:10605628, PubMed:14719035, PubMed:12554744). Has growth-promoting activities on intestinal epithelium (PubMed:10605628, PubMed:14719035, PubMed:12554744). May also regulate the hypothalamic pituitary axis (HPA) via effects on LH, TSH, CRH, oxytocin, and vasopressin secretion (PubMed:10605628, PubMed:14719035, PubMed:12554744). Increases islet mass through stimulation of islet neogenesis and pancreatic beta cell proliferation (PubMed:10605628, PubMed:14719035, PubMed:12554744). Inhibits beta cell apoptosis (PubMed:10605628, PubMed:14719035, PubMed:12554744). {ECO:0000269|PubMed:22037645, ECO:0000269|PubMed:40446798, ECO:0000303|PubMed:10605628, ECO:0000303|PubMed:12554744, ECO:0000303|PubMed:14719035}. [Glucagon-like peptide 2]: Stimulates intestinal growth and up-regulates villus height in the small intestine, concomitant with increased crypt cell proliferation and decreased enterocyte apoptosis. The gastrointestinal tract, from the stomach to the colon is the principal target for GLP-2 action. Plays a key role in nutrient homeostasis, enhancing nutrient assimilation through enhanced gastrointestinal function, as well as increasing nutrient disposal. Stimulates intestinal glucose transport and decreases mucosal permeability. {ECO:0000303|PubMed:10322410, ECO:0000303|PubMed:10605628, ECO:0000303|PubMed:12554744, ECO:0000303|PubMed:14719035}. [Oxyntomodulin]: Significantly reduces food intake. Inhibits gastric emptying in humans. Suppression of gastric emptying may lead to increased gastric distension, which may contribute to satiety by causing a sensation of fullness. {ECO:0000303|PubMed:10605628, ECO:0000303|PubMed:12554744}. [Glicentin]: May modulate gastric acid secretion and the gastro-pyloro-duodenal activity. May play an important role in intestinal mucosal growth in the early period of life. .