In accordance with its association with poor prognostic in patients, CD151 has been implicated as a promoter of tumor angiogenesis and/or metastasis in vitro in human breast cancer cell lines and in several in vivo model systems including xenografts [5,11], matrigel plug and tumor implantation experiments [12], as well as experimental metastasis models [13,14]. This evidence concerns the gene CD151 and breast cancer.