OOSP1 (oocyte secreted protein 1) is a novel secreted protein primarily expressed in oocytes that mediates oocyte-somatic cell communication essential for normal ovarian function 1. The protein is a 202-amino acid secreted factor containing a signal peptide, five N-linked glycosylation sites, and six cysteines predicted to form three disulfide bonds 1. OOSP1 shares structural homology with placental-specific protein 1 (PLAC1) and possesses a zona pellucida (ZP)-N domain motif that enables polymerization into filaments—a structural feature shared across the OOSP family 2. The Oosp1 gene spans over 16.4 kb with five exons and localizes to human chromosome 11-11q13 1. Functionally, OOSP1 has been proposed to participate in ovarian folliculogenesis through paracrine signaling. However, recent CRISPR/Cas9 knockout studies revealed that triple knockout of Oosp1, Oosp2, and Oosp3 resulted in decreased prolificacy but retained fertility, suggesting these genes may be dispensable for reproductive function despite their oocyte-enriched expression 3. The precise physiological role of OOSP1 in fertility and follicle development remains incompletely understood and requires further functional characterization.