GPR49/LGR5 (G protein-coupled receptor 49/leucine-rich repeat-containing G protein-coupled receptor 5) is also known by the names FEX, GPR67, GRP49, HG38, and MGC117008). It is an orphan receptor and structurally related to members of the mammalian large transmembrane glycoprotein hormone receptor family (FSH-R, TSH-R, and LH-R).