DKK1 and central nervous system cancer: The levels of cerebral fluid DKK-1 protein were significantly higher in glioma patients than in healthy donors or in neuronal benign tumor patients (P < 0.05); the difference between healthy individuals and neuronal benign tumor patients was not significant (Figure 4B), suggesting that the DKK-1 molecule secreted and stably expressed in cerebral fluids can also be applicable to detect presence of glioblastoma and to develop novel prognostic treatments.