SERPINE2 and ductal breast carcinoma in situ: Comparing Pure DCIS with Not Pure DCIS for all samples with reduced expression for 3–4 progressor genes we found a number of DEGs (Table S3) previously associated with invasion and metastatic potential that were expressed at consistent levels (correlating with reduced metastasis) for all Pure DCIS samples, including SERPINE2 and SLPI, both genes found to influence metastasis and contribute to vascular mimicry in a mouse model of breast cancer66.