S100A10 and breast carcinoma: To circumvent these experimental challenges, and to advance our understanding of the role of p11 in oncogenesis, we have established the MMTV-PyMT (mouse mammary tumor virus-polyoma middle tumor-antigen) transgenic breast cancer model in wild-type and p11 knockout mice and have used this double transgenic model to investigate the role of p11 in breast cancer malignancy.