In the past decade, a number of studies have been performed to explore the relationship between three common XRCC1 single nucleotide polymorphisms (SNPs)—Arg399Gln (base G to A polymorphism), Arg194Trp (base C to T polymorphism), and Arg280His (base G to A polymorphism)—and leukemia risk. This evidence concerns the gene XRCC1 and leukemia.