Blotting, Northern|Breast Neoplasms|Cell Division|Cell Line, Tumor|Computational Biology|DNA, Complementary|Epithelial Cells|Gene Expression Profiling|Gene Expression Regulation, Neoplastic|Humans|Models, Genetic|Neuregulin-1|Oligonucleotide Array Sequence Analysis|RNA, Neoplasm|Recombinant Proteins|Research Design