Next, we measured expression levels of all Fzd genes in these mammary tumors by quantitative real-time (qRT)-PCR and found that only Fzd7 was expressed at higher levels in both p53/BRCA1-deficient and C3(1)-Tag tumors, but not in MMTV-PyMT tumors, than all other Fzd genes (Fig 1D). This evidence concerns the gene FZD7 and breast cancer.