G protein-coupled receptors (GPCRs), also designated seven transmembrane (7TM) receptors and heptahelical receptors, are a protein family which interact with G proteins (heterotrimeric GTPases) to synthesize intracellular second messengers such as diacylglycerol, cyclic AMP, inositol phosphates and calcium ions. Their diverse biological functions range from vision and olfaction to neuronal and endocrine signaling and are involved in many pathological conditions. The GPCR family represents the largest class of targets for modern drugs. Leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6) is an orphan-A GPCR with an N-terminal ectodomain comprising variable leucine-rich repeats, a 7TM region and a unique C-terminal intracellular tail. The sequence of LGR6 is similar to TSHR, FSHR and LHR. LGR6 is predominantly expres-sed in the adrenal gland, ovary and uterus.