XRCC3

X-ray repair cross-complementing protein 3 (XRCC3), encoded by the XRCC3 gene, is a RAD51 paralog critical for homologous recombination repair (HRR) of double-strand DNA breaks. It forms a functional complex with RAD51B/C/D and XRCC2 to stabilize RAD51 nucleoprotein filaments, supporting accurate DNA repair under the ATM/ATR-mediated damage response pathway.
Impaired XRCC3 function disrupts HRR, leading to genomic instability and elevated risk of BRCAness-associated cancers (e.g., breast, ovarian). Preclinical data indicate XRCC3-deficient tumors exhibit synthetic lethality with PARP inhibitors, prompting early-phase trials to evaluate these agents as targeted therapies for such malignancies.