SMN1 and breast cancer: We also detected a blood vessel heterogeneity in BC tumor stroma containing a mixture of immature blood vessels with a discontinuous wall (IMBV_CD34+/SMA−, known to be one of the disseminating routes for malignant cells) and mature blood vessels (MBV_CD34+/SMA+, which are stable vessels with silent, inactive endothelial cells and a well-defined wall mimicking normal blood vessels).