By the first time, we analyzed genotypes and haplotypes of four SNPs located in genes whose protein products participate in the Wnt/β-catenin signaling pathway: rs1133683 (C/T) and rs2240308 (C/T) of the AXIN2 gene and rs7903146 (C/T) and rs12255372 (G/T) of the TCF7L2 gene; the results achieved here suggest that the AXIN2 rs2240308 and TCF7L2 rs7903146 and rs12255372 variants play a significant role in promoting breast cancer. The gene discussed is TCF7L2; the disease is breast carcinoma.