PECAM1 and glioblastoma: Significant differences between glioblastoma samples and healthy controls were observed for angiopoietin, follistatin, HGF, IL-8, PDGF-BB, PECAM-1 and leptin, with specificity ranging from 59–81% and sensitivity from 40–88%, while infrared-spectroscopy reached 100% sensitivity and 87.5% specificity.