Here, we report that neurofibromin knockdown was associated with increases in expression and secretion of platelet-derived growth factor AA (PDGF-AA) and interleukin-8 (IL-8), two factors that influence tumor angiogenesis and inflammatory cell recruitment, and chitinase-3-like protein 1 (CHI3L1) and endoglin (ENG), two markers of the mesenchymal gene expression subclass in GBM. The gene discussed is CHI3L1; the disease is neoplasm.