SERPINE1 and breast cancer: uPA and PAI-1 are supposed to be useful in deciding upon adjuvant systemic therapy in women with low-risk primary breast cancer.7 Use of PAI-1 for therapeutic purposes has shown promising results on tumour models; however, the results are yet to be confirmed.9 The increase of PAI-1 could represent a response to the increased proteolytic activity caused by uPA inside the tumour.