GHSR is a G-protein-coupled seven-transmembrane receptor. The GHSR gene (GHSR) is located at chromosome 3q26.31 and consists of two exons and one intron. Two types of GHSR mRNA, GHSR-1a and GHSR-1b, are produced through alternative splicing. GHSR-1a contains all seven-transmembrane domains and possesses high affinity binding to ghrelin. GHSR-1b mRNA is encoded by exon 1 and the intronic region, and it is physiologically inactive. The highest expression levels of GHSR-1a are found in the central nervous system (CNS) and in the pituitary gland, while lower expression is detected in other peripheral organs, including adrenal glands, the heart, thyroid glands, and adipose tissue.