As far as we are aware, this is the first report of this type, using live cultured ex vivo breast cancer tissue for a period of 25 days Recent work demonstrated that tumor grafts from breast cancer patients cultured in mice, accurately replicate tumor growth, metastatic potential and pathology of the major breast cancer classifications [44], and importantly, conserve the histological markers and features of the original tumor such as HER2 and ER positivity, as well as proliferation indices [45]. This evidence concerns the gene ERBB2 and breast cancer.