Male-specific phermone which is recognized by the Vmn2r116/V2rp5 receptor in the vomeronasal organ (VNO) and enhances female sexual receptive behavior (lordosis) upon male mounting, resulting in successful copulation. Monomer. Secreted by the extraorbital lacrimal gland into tears. Expressed in the extraorbital lacrimal gland from where it is secreted into tears. Expression is observed after 4 weeks of age in males only. Not expressed in females or in males castrated at 3 weeks of age whereas expression is not down-regulated in castrated adult males. Expressed at very low levels in most inbred strains with high levels detected only in strains BALB/c and DBA/2. Expressed at high levels in a number of wild mouse-derived strains. Belongs to the exocrine gland-secreted peptide family.