Human growth hormone (hGH) plays an important role in growth control. Its major role in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. The effects of hGH in the body can be generally described as anabolic. It stimulates amino acid uptake and protein synthesis in muscle and other tissues. Growth Hormone (GH1) is synthesized by acidophilic or somatotropic cells of the anterior pituitary gland. Genes for growth hormone (GH) are found in a gene cluster on 17q, which consists of two growth hormone genes and three CSH genes. The GHN1 gene is transcribed exclusively in the pituitary, whereas the other 4 genes are expressed only in placental tissues. Several isoforms of GH1 exist. Human growth hormone (hGH) is also used as a reporter protein, because it is secreted from mammalian cells it can be assayed by ELISA on culture supernatant using antibodies to determine the level of expression.