EIF2AK3 and central nervous system cancer: For example, a recent study examining human gliomas found coordinated up-regulation of UPR targets and glycolysis, which correlated with poor patient prognosis (Epple et al. 2013); and both ER stress (Win et al. 2013) and overexpression of Perk (Muñoz et al. 2013) have been shown to reduce mitochondrial respiration in cultured mammalian cells.