RT-PCR of 37 glioma specimens, out of which 17 were grade IV GBM tumors, showed that NRP1 mRNA expression is higher in GBM than in non-tumoral tissue and lower-grade gliomas, and glioma patients with NRP1 overexpression (56.8%) showed a poorer prognosis indicated by reduced overall survival [102]. Here, NRP1 is linked to glioma.