A comparative Western blot analysis between the paired sets of breast tissue (paired normal and primary cancer from the same individual; paired primary and metastatic cancer from the same individual) and the paired sets of other tissues (lung and colon) revealed preferential overexpression of Prx I and Trx1 proteins in breast cancer compared with those in lung and colon cancer, and higher protein levels of Prx I and Trx1 in metastatic breast cancer than in primary breast cancer (Figure 9). This evidence concerns the gene TXN and metastatic malignant neoplasm.