The inventors found that the gene, HOXB7, was frequently overexpressed in breast cancer, and is a major upstream regulator of events leading to tamoxifen resistance. The present invention provides double-stranded short interfering nucleic acid (siNA) molecules that targets the HOXB7 gene in cells, and also provides methods of use of this siNA molecule for methods of screening, diagnosis and prediction of treatment outcomes as well as treatment of cancer.
