CDX2 and breast cancer: The analysis of Cdx2 polymorphism across our panel of breast cancer cell lines evidenced the presence of different Cdx2 genotypes: AG in MDA-MB-231, SUM 159PT, MCF7 and T-47D, GG in HCC1143, BT20 and HCC1954 and AA in SK-BR-3, BT549 MDA-MB-468.