We also found that CSF Nogo-A concentrations were nearly 10-fold lower in the astrocytic brain tumor group and 7-fold lower in the group of tumors of the meninges compared to non-tumoral subjects (3452 pg/mL; IQs:1471–5000 pg/mL) (P < 0.001 and P = 0.003, respectively) (Figure 1). This evidence concerns the gene RTN4 and tumor of meninges.