In this study, a significant high serum level of TPA was detected in breast cancer patients compared with healthy control group but significant lower TPA serum level in breast cancer patients who received 6 cycles of chemotherapy than those who did not received chemotherapy yet (Table II and III), which mean that serum TPA level have a good predictive value for response to chemotherapy and normally decrease in response to successful treatment. This evidence concerns the gene PLAT and breast carcinoma.