Literature search for the 29 differentially expressed proteins identified in this study showed 6 of them to have an association with GnRH signaling pathway including KNG1, AHSG, AFP, FRG1, lactotransferrin isoform 2 (LTF), peroxisome proliferator-activated receptor delta isoform 4 (PPARD), while the remaining 23 proteins are novel to GnRH signaling in GBM or other cancers, which includes ITIH2 and ITIH4. Here, PPARD is linked to glioblastoma.