Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo, which eventually forms the placenta after implantation. The presence of hCG is detected in some pregnancy tests. Some cancerous tumors produce this hormone; therefore, elevated levels measured when the patient is not pregnant may lead to a diagnosis of cancer and, if high enough, of paraneoplastic syndromes. It is unknown however whether this production is a contributing cause or an effect of carcinogenesis. The pituitary analogue of hCG, luteinizing hormone (LH), is produced in the pituitary gland of males and females of all ages.