OOEP (oocyte expressed protein) is a core structural component of the subcortical maternal complex (SCMC), a multiprotein scaffold essential for early embryonic development 1. OOEP localizes to cytoplasmic lattices in oocytes and preimplantation embryos, where it functions as part of the SCMC to store and stabilize maternal proteins critical for embryonic development 2. Beyond structural roles, OOEP participates in DNA damage response pathways: as part of an OOEP-KHDC3 scaffold, it recruits BLM and TRIM25 to stalled replication forks, promoting replication fork restart, and positively regulates homologous recombination-mediated double-strand break repair by regulating ATM activation and RAD51 recruitment, thereby supporting oocyte survival and meiotic completion. OOEP also interacts with NLRP5 to stabilize UHRF1 in the cytoplasm, contributing to epigenetic reprogramming 3. Mutations in OOEP cause human female infertility characterized by early embryonic arrest, with compound heterozygous variants reducing OOEP protein levels and resulting in developmental arrest at preimplantation stages 4. These findings establish OOEP as essential for maternal contribution to early embryogenesis and implicate its dysfunction in reproductive disorders 5.