Biomarkers, Tumor|Breast Neoplasms|Cell Line, Tumor|Computational Biology|Cyclin-Dependent Kinase Inhibitor p27|ErbB Receptors|Female|Gene Knockdown Techniques|Genes, erbB-2|Humans|MAP Kinase Signaling System|Mutation|Neoplasms|Phosphatidylinositol 3-Kinases|RNA, Messenger|RNA, Neoplasm|Receptor, ErbB-2|Receptor, ErbB-3