Relaxins are known endocrine and autocrine/paracrine hormones, belonging to the insulin gene superfamily. In the human there are three non-allelic relaxin genes, RLN1, RLN2 and RLN3. RLN1 and RLN2 share high sequence homology. This encoded protein is synthesized as a single-chain polypeptide but the active form consists of an A chain and a B chain linked by disulfide bonds; however, their exact cleavage sites have not been described. Relaxin is produced by the ovary, and targets the mammalian reproductive system to ripen the cervix, elongate the pubic symphysis and inhibit uterine contraction. It may have additional roles in enhancing sperm motility, regulating blood pressure, controlling heart rate and releasing oxytocin and vasopressin. This gene has multiple polyadenylation sites. There are multiple alternatively spliced transcript variants described for this gene but their full length nature is not known yet.