DPP4 and cancer: DPP4 (plasma membrane protein that contributes to immune and metabolic regulation [95, 96]) and HB-EGF (cell metabolic activity and tumor suppression in other cancers [95–97]) were also strongly upregulated in GBM-MG co-culture, as was ANG, well-known for its role in angiogenesis and cell proliferation [98, 99], and Serpin F1, known as for its role in suppression of tumor growth and prostate cancer metastasis [100–103].