Breast CAFs are closely correlated with tumor angiogenesis. (A) HE staining to show vessel-like structures in the stroma of para-cancer and cancer tissues. Scale bar, 200 μm. (B) CD31 staining to show the different distribution of MVD in breast cancer stroma and the cancer nest area. Scale bar, 50 μm. (C) Expressions of CD31 and α-SMA (CAFs marker) in ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC) and metastatic carcinoma. Scale bar, 200 μm. (D) A positive correlation is shown between α-SMA protein levels and MVD in different clinical breast cancer tissues. (Pearson's correlation test, P<0.01). (E) Heatmap to illustrate the hierarchical clustering of altered angiogenesis-associated genes in CAFs and their paired NFs. (F-I) The cell proliferation (F), invasion (G), and tubule formation (H-I) (Scale bar, 300 μm) abilities of human endothelial cells (HUVECs) were tested under co-culture with the conditioned medium (CM) from CAFs or the paired NFs with Axitinib (H), or the CM neutralized with the anti-VEGF antibody (I). (n=3; *P<0.05; **P<0.01).