We isolated 12 pairs of primary CAFs and corresponding NFs from breast cancer and noncancer tissues, and the purities of CAFs were identified by the activated fibroblast biomarkers α-SMA, FAP and vascular endothelial marker CD31 (a biomarkers of endothelial cells as control) as previously reported (Figure S1A). The gene discussed is PECAM1; the disease is breast carcinoma.