GPR25 is intronless and encodes a member of the G-protein coupled receptor 1 family. This receptor is activated by Apelin and Apela in non-mammalian organisms. G-protein coupled receptors are membrane proteins which activate signaling cascades as a response to extracellular stress. This gene has been linked to arterial stiffness. In immunohistochemistry, GPR25 has membranous positivity in immune tissues and in blood, on neuroendocrine cells and surface epithelial cells in the gastrointestinal tract, on some neurons in the amygdala and on populations of epithelial cells in the anterior pituitary. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804