Analysis of the cellular localization of these proteins in four frozen glioblastoma biopsy samples by triple-label immunofluorescence indicated cytoplasmic co-expression of FIP200 and Pyk2 in endothelial cells in tumor-associated blood vessels identified by vWf expression (Figure 8A1&2), suggesting that FIP200 and Pyk2 are localized in a manner that is consistent with their potential association. This evidence concerns the gene RB1CC1 and glioblastoma.