The frequency of the A allele is 74% in Africans, 43% in Asians and 19% in Caucasians [39].The A allele allows the Cdx2 transcription factor to bind more effectively, thereby increasing VDR transcriptional activity thus decreasing the breast cancer incidence [40], whereas the G allele has the opposite effect [34,36]. Here, CDX2 is linked to breast cancer.