RFWD3 also known as RNF201 is an E3 ubiquitin-protein ligase implicated in the DNA damage response, where it helps coordinate ubiquitin-dependent signaling at stalled replication forks and sites of genotoxic stress. RFWD3 activity supports genome stability by promoting processing of DNA lesions and regulating repair factor turnover within pathways such as homologous recombination and replication stress signaling. Disruption or dysregulation of RFWD3 has been linked to impaired DNA repair capacity, elevated chromosomal instability, and altered cellular sensitivity to replication stress, making it relevant to studies of tumor biology and inherited DNA maintenance defects.