HROB (homologous recombination factor with OB-fold) is a DNA-binding protein that plays a critical role in homologous recombination and DNA damage repair. The protein functions by recruiting the MCM8-MCM9 helicase complex to sites of DNA damage, where its C-terminal OB-fold domain stimulates helicase activity by altering the complex's conformation 1. HROB binds to the stable MCM8-MCM9 heterodimer with high affinity and promotes DNA unwinding at branched DNA structures, acting downstream of MCM8-9 loading and ring formation on single-stranded DNA 1. The protein is structurally characterized as largely intrinsically disordered with a helix-rich region and canonical OB-fold motif 2. HROB expression is cell cycle-regulated, peaking during S phase when DNA replication occurs 2. Clinically, biallelic variants in HROB are associated with primary ovarian insufficiency (POI), a condition affecting 1-3% of women under 40 and causing infertility and increased health risks 34. The identification of HROB variants in POI patients highlights its essential role in meiosis and ovarian function, positioning it as both a diagnostic marker and potential therapeutic target for reproductive disorders 3.