Additionally studies have used different methods to determine AR expression (immunohistochemistry and gene expression profiling) and different cut offs (e.g. staining of ≥1% of cells or ≥ 10% of cells) to identify AR positive tumours by immunohistochemistry [10, 12, 29] Other factors that may have contributed to the low level of AR expression in this study include the exclusion of women who had received neo-adjuvant chemotherapy and false negativity due to the instability of the AR protein in stored tissue blocks. This evidence concerns the gene AR and neoplasm.