This SCP-like extracellular protein domain is found in the glioma pathogenesis-related protein (GLIPR) subfamily, which consists of GLIPR1, GLIPR1-like 1 (GLIPR1L1), and GLIPR1-like 2 (GLIPR1L2). GLIPR1 and GLIPR1L2 are expressed in several tissues, whereas GLIPR1L1 is expressed predominantly in the testis and is involved in the binding of sperm to the oocyte complex [, ].The SCP domain is also known as CAP domain []. The wider family of SCP containing proteins includes plant pathogenesis-related protein 1 (PR-1), CRISPs, mammalian cysteine-rich secretory proteins, which combine SCP with a C-terminal cysteine rich domain, and allergen 5 from vespid venom. It has been proposed that SCP domains may function as endopeptidases.
