In view of recent findings, which demonstrated the inhibitory action of fenofibrate against IGF-IR signaling [12], we evaluated IGF-IR, its major signaling molecule, Insulin Receptor Substrate 1 (IRS-1), and PPARα protein levels in five human Glioma cell lines in comparison to primary cultures of human fetal astrocytes. The gene discussed is IGF1R; the disease is glioma.