XRCC2 and breast cancer: Two single nucleotide polymorphisms (SNPs) [rs3218550:NC_000007.14:g.152646870C>T, X-ray repair cross-complementing gene-2 (XRCC2)/7q36.1; and rs6917:NC_000017.11:g.49404181G>A, prohibitin-1 gene (PHB)/17q21.33] showed the strongest evidence for association with breast cancer risk.