GFAP plasma levels were significantly higher in patients with glioblastoma (n = 37; median 610 pg/mL [interquartile range 263.5–1877.5]) compared to other tumors (n = 64; 81.5 pg/mL [40.3–197.3]; p < 0.001). This evidence concerns the gene GFAP and glioblastoma.