Mammary tumors from Cre+ mice treated with DMBA following Cx26 knockout had similar palpable tumour onset (75±14 days) compared to Cre- mice (60±10 days) suggesting that despite an increased frequency of developing mammary tumors, tumors arose at comparable times in Cre+ and Cre- mice (Figure 3A). This evidence concerns the gene GJB2 and breast cancer.