Progesterone-Associated Endometrial Protein （PAEP） is a member of the kernel lipocalin super family whose members share rather low sequence similarity but have highly conserved exon/intron structure and three-dimensional protein folding. Most lipocalins are clustered on the long arm of chromosome 9. PAEP protein has been previously referred to as pregnancy-associated endometrial alpha-2-globulin， placental protein 14， and glycodelin.
