Expressed in placenta (at protein level) (PubMed:10803597, PubMed:10537154, PubMed:16876275). Expressed in the tail hair follicle, with highest expression detected in the keratinocytes of the outer root sheath (PubMed:10803597). Expressed in ear skin with lesser amounts in small intestine (PubMed:10803597). Not detected in brain at 18 dpc, postnatal day 25 or postnatal day 55 (PubMed:16876275). In placenta, detected at 8 dpc, peaks at 12 dpc and declines thereafter. N-glycosylated and sialylated. Belongs to the somatotropin/prolactin family.