The results of the qRT-PCR analysis demonstrated that PLAT, SERPINA1, HMGCS2, and MMP7 were significantly downregulated in IDC tissues, compared with the DCIS tissues (all p<0.05, Figures 9A–D), which were consistent with the results obtained from the GSE26304 data set. Here, SERPINA1 is linked to ductal breast carcinoma in situ.