Prss21, also known as testisin, is a gene encoding a glycosyl-phosphatidylinositol-linked serine protease. It is involved in multiple biological functions, such as regulating physiological angiogenesis, endothelial permeability, and sperm cell maturation. In the context of ovarian cancer, it plays a role in the tumor microenvironment and metastasis-related pathways [1].

In mouse models, Prss21-deficient mice show increased vascular permeability and a hemorrhagic phenotype during luteal angiogenesis, with impaired microvascular endothelial cell reorganization and increased paracellular permeability [2]. In terms of sperm function, Prss21-deficient spermatozoa have decreased motility, abnormal tails, and impaired fertilizing ability. Double-knockout mice lacking Prss21 and other sperm-related proteins like ACR are subfertile, and their sperm are infertile in vitro, highlighting the role of Prss21 in sperm penetration through the cumulus matrix and zona pellucida [3,4,6]. Fluoride exposure, which downregulates Prss21 expression in rat epididymis, reduces sperm's ability to break down the egg cumulus cell layer [5].

In conclusion, Prss21 is essential for normal physiological functions, including angiogenesis and sperm maturation. The use of gene-knockout mouse models has revealed its role in these processes. In the context of diseases, it has implications for ovarian cancer metastasis and male infertility, providing insights into potential therapeutic targets for these conditions.