Binds specifically to type I collagen. Probably secreted from the basolateral region of the cell near the extracellular matrix. Expressed in placenta, where it is detected in both fetal tissues (cotyledon and intercotyledon) and maternal tissues (caruncle and intercaruncular endometrium) (at protein level) (PubMed:19503832, PubMed:23759217). Expressed in the mesenchyme area of villi in the cotyledon (at protein level) (PubMed:19503832, PubMed:23759217). In endometrium, expressed in the luminal epithelium and weakly in the subluminal stroma (at protein level) (PubMed:23759217). Detected in trophoblast mononucleate cells (TMCs) (at protein level) (PubMed:19503832). Also detected in trophoblast binucleate cells (BNCs) (PubMed:23759217). Overall, expression is strongest in fetal tissue and lower in maternal tissue (PubMed:19503832, PubMed:23759217). Not detected in other tissues tested (PubMed:19503832). Detected in the placenta from day 11 of gestation onwards (PubMed:19503832, PubMed:23759217). Expressed in the conceptus at the pre- and peri-implantation stages (gestational days 11-21) (PubMed:19503832). Expressed in the extra-embryonic membrane at the post-implantation stage (gestational days 27-33), although expression appears to decline temporarily at gestational day 27 (PubMed:19503832). Expressed in cotyledon from early to late gestation (gestational days 60 to 250), with highest expression levels at gestational day 60 and declining expression thereafter (PubMed:19503832, PubMed:23759217). Also expressed in intercotyledon from gestational day 60 onwards, reaching maximum expression levels during late gestation (PubMed:19503832, PubMed:23759217). Expressed in caruncle from early to late gestation, reaching maximum expression at the late gestation stage (PubMed:23759217). Has low expression in intercarunclar tissue during early gestation, but expression levels increase by mid gestation and remain high during late gestation (PubMed:23759217). Glycosylated.