MDM2 and breast cancer: The list of potential risk factors for BC in Kyrgyz females may include 399Gln allele and Arg399Gln of gene XRCC1 heterozygous genotype, as well a combination of heterozygous genotypes of Arg399Gln/Arg72Pro of genes XRCC1/TP53, Arg399Gln/T309G of genes XRCC1/MDM2 and Arg399Gln/Arg72Pro/T309G of genes XRCC1/TP53/MDM2.