EIF2AK4 and glioblastoma: Mechanistically, stress-sensing protein kinases PERK and GCN2 phosphorylate eIF2α in response to glucose deprivation, and the transcription factor ATF4, activated by eIF2α phosphorylation-mediated selective translation, induces the expression of fructolytic genes, leading to a fructolysis-dependent GBM growth.