Progesterone-induced-blocking factor 1 is a protein that in humans is encoded by the PIBF1 gene. It has been shown to localize to the centrosome and has also been named CEP90. 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 NK activity exerts an anti-abortive effect.
