The inherent over expression of PDGFRα in p-CSC pools suggests this as a molecular signature of the GBM peritumor tissues, while PDGFRβ was expressed either in c-CSC or p-CSC of the six cases examined (although we have documented increasingly expression levels in p-CSC pools except for Case 6) (Figure 1E). Here, PDGFRA is linked to glioblastoma.