article 6 controlled study 6 unclassified drug 6 Cell Hypoxia 4 Cell Line 4 Cell Line, Tumor 4 Cell Survival 4 Eukaryotic Initiation Factor-2 4 HeLa Cells 4 Humans 4 PERK protein 4 Proto-Oncogene Proteins c-akt 4 activating transcription factor 6 4 cell death 4 cell fate 4 cell protein 4 eIF-2 Kinase 4 human 4 human cell 4 hypoxia 4 initiation factor 2alpha 4 inositol requiring protein 1 4 phosphatidylinositol 3 kinase 4 physiological process 4 protein kinase B 4 protein phosphorylation 4 protein protein interaction 4 protein targeting 4 protein unfolding 4 signal transduction 4