In our study, the MEs express PAI-1 in all high-grade DCIS (n=24), whereas anti-PAI-1 immunoreaction of MEs in non-high-grade DCIS without comedo-type necrosis (VNs group I) was found in only two of 20 cases and in non-high-grade DCIS with comedo-type necrosis (VNs group II) in eight of 16 cases. This evidence concerns the gene SERPINE1 and ductal breast carcinoma in situ.