CSPG4 and glioblastoma: Whereas the pericyte population marked by expression of 2161F9-reactive isoforms structured the entire luminal surfaces of glioblastoma vessel walls, in partial continuity with the Coll IV-containing stratified VBM and in a contiguous manner with the surrounding Coll VI (Figures 3A, B), the pericyte phenotype revealed by this isoform in foetal brain corresponds to single, often isolated pericytes, which were clearly seen to embrace the microvessel wall with short processes and partially cover the Coll IV/Coll VI/NG2/CSPG4 D2-containing VBM (Figures 3G-I).