CRLR (calcitonin receptor-like receptor) and CD 117, the gene product of c-kit have been shown to be expressed in cells of glial tumors, especially in those with higher malignancy. Here we report the distribution of these peptides in various cellular compartments within those tumors. Both receptor proteins have been investigated in 95 glial tumor biopsies of different grades. Both proteins were visualized by immunohistochemistry with antibodies either commercially available or raised for this purpose. Both receptor peptides can be identified in or around tumor blood vessels. CRLR occurs in some endothelial cells, especially in the microvascular proliferations of glioblastoma multiforme, whereas CD 117 preferentially occurs in cells of the thickened vascular wall within cells of pericyte or fibroblast morphology. Both antigens are found in addition in few neoplastic cells of overt astrocyte morphology. The occurrence of identical antigens in glial tumor blood vessels and in neighboring tumor cells underlines the common origin of "mesenchymal" and "neuroepithelial" components of such (malignant) glial neoplasms.