Moreover, women who carried the XRCC1-399 Gln/Gln genotype and were diagnosed with early stage (I or II) breast cancer had tumours of higher grade (II or III) marginally (p = 0.065, one-sided) more often than those with the Arg/Arg genotype, 86.1% (31/36) versus 72.5 % (137/189), respectively. The gene discussed is XRCC1; the disease is breast cancer.