IGFBP6 and glioblastoma: We confirmed the diagnostic ability of IGFBP6 to discriminate the glioblastoma patients from healthy subjects (AUC = 0.826, P < 0.0001) (Fig. 8D) or from the patients affected to astrocytoma (AUC = 0.753, P < 0.0001) (Fig. 8E) or oligodendrocytoma (AUC = 0.748, P < 0.0001) (Fig. 8F).