Using immunofluorescence, we detected limited co-localization of TEM1/endosialin and FN in GBM and metastatic brain tumor sections, suggesting that physiologic interactions between TEM1/endosialin and FN may occur, but that such interactions are not extensive in clinical settings of CNS neoplasia (Fig 2 and Additional file 1). Here, CD248 is linked to glioblastoma.