CD31/PAS analysis revealed a 3-4-fold reduction in the number of VM channels (CD31NEG/PASPOS) upon Foxc2 knockdown (Fig 3G and 3H), indicating that Foxc2 is required for VM in vivo, whilst the number of CD31POS/PASPOS endothelial vessels increased (Fig 3G and 3H) suggesting an increase in angiogenesis and a potential crosstalk between these two tumor vascularization modes. Here, PECAM1 is linked to neoplasm.