In accordance to the mRNA data, the protein content of GFAP was not significantly altered in GBM tissue compared to nonmalignant brain (relative protein values: 1.09, Min–Max: 0.37–4.04 versus 1.03, Min–Max: 0.74–1.26), while Sparc protein expression was significantly upregulated in GBM from 1.01 (Min–Max: 0.44–1.54) in control brain tissue to 8.14 (Min–Max: 1.16–82.85; Figure 4(a)). Here, GFAP is linked to glioblastoma.