Enables signaling receptor binding activity. Involved in mammary gland development; regulation of apoptotic process; and spermatogenesis. Acts upstream of or within prostate gland growth and regulation of nitric oxide mediated signal transduction. Predicted to be located in extracellular region. Is expressed in fetal Leydig cell; ovary; and thymus. Orthologous to several human genes including RLN1 (relaxin 1). [provided by Alliance of Genome Resources, Apr 2022]