Double immunolabellings performed with mAb 2161F9 and antibodies to Coll IV and Coll VI (Figure 3A, B) or the pAb NG2/CSPG4 D2 (Figure 3C-F) revealed that in glioblastoma tissues these specific isoforms accumulated at the endothelium/pericyte interface and thereby, as compared with NG2/CSPG4 D2, immunolocalized the innermost pericyte subset (Figure 3C). The gene discussed is CSPG4; the disease is glioblastoma.