The breast cancer susceptibility proteins BRCA1 (also known as FANCS), BRCA2 (FANCD1), and RAD51 (FANCR) and its paralogs, including XRCC2 (FANCU) and XRCC3, all serve a function in homologous recombination repair (HRR). The gene discussed is XRCC2; the disease is breast carcinoma.