Expression of CREB3L1, GRP78 and CHOP in World Health Organization grade I-Ⅳ glioma tissues detected by immunohistochemistry (magnification, x400). Values are expressed as the mean ± standard deviation (n=3). **P<0.01 vs. grade I. CREB3L1, cyclic adenosine monophosphate responsive element binding protein 3 like 1; CHOP, C/EBP-homologous protein; GRP78, glucose-regulated protein, 78 kDa.