Plays a role in ciliogenesis. Pericentriolar protein required to maintain mitotic spindle pole integrity (PubMed:21224392). Required for the centrosomal accumulation of PCM1 and the recruitment of centriolar satellite proteins such as BBS4. Via association with PCM1 may be involved in primary cilia formation (PubMed:23110211). Required for CEP63 centrosomal localization and its interaction with WDR62. Together with CEP63 promotes centriole duplication. Promotes the centrosomal localization of CDK2 (PubMed:26297806). The secreted form is a mediator of progesterone that by acting on the phospholipase A2 enzyme interferes with arachidonic acid metabolism, induces a Th2 biased immune response, and by controlling decidual naturakl killer cells (NK) activity exerts an anti-abortive effect (PubMed:14634107, PubMed:3863495, PubMed:12516630). Increases the production of Th2-type cytokines by signaling via the JAK/STAT pathway. Activates STAT6 and inhibits STAT4 phosphorylation. Signaling via a not identified receptor seems to implicate IL4R and a GPI-anchored protein (PubMed:16393965, PubMed:25218441). Isoform 1 interacts with PCM1, BBS4 and CEP63 (PubMed:21224392, PubMed:23110211, PubMed:26297806). Interacts with IL4R (PubMed:25218441). In progesterone-treated astrocytoma cells a 57 kDa protein and isoform 1 (90 kDa) have been described, both being located in the intracellular medium and secreted. Respective predominant forms are isoform 1 in the intracellular and the 57 kDa protein in the extracellular medium (PubMed:25218441). Localizes to centriolar satellites throughout the cell cycle. Secreted by progesterone-treated lymphocytes (PubMed:14634107). Additional isoforms seem to exist. Expressed at highest levels in testis. Moderate expression is detected in spleen, thymus, prostate, ovary, small intestine, and colon (PubMed:11935316). Expressed in the first trimester pregnancy decidua (PubMed:12516630). Localized to extravillous cytotrophoblast (at protein level). Also found in syncytiotrophoblast and part of the villous cytotrophoblast. Isoform 1 is expressed in first trimester and term villous trophoblast; trophoblast cells can additionally express other isoforms (PubMed:18817979). Overexpressed in solid tumors from stomach and uterus and in cells from ovary, cervical, breast, lymphoma and leukemia cancer (PubMed:25218441). By progesterone. May be associated with microcephaly. The disease is caused by variants affecting the gene represented in this entry. During normal pregnancy, the production is continuously increasing until the 37th gestational week and is followed by a sharp decrease after the 41st week of gestation. In pathological pregnancies, urinary levels fail to increase. Candidate for the diagnosis of threatened premature pregnancy termination.