ATF4 and neoplasm: Additionally, many central components of the ATF4- and CHOP-dependent pro-apoptotic stress-response pathway such as ATF4, DDIT3 (CHOP), PPP1R15A (GADD34), ATF3, HERPUD1 and GADD45A45, 46, 47, 48 were among the hits that show the highest upregulation after Fluphenazine–DFO co-treatment (see Figure 6a).15 We confirmed these results in hypoxic tumor spheroids (Figure 6b), which show a strong hypoxia-specific upregulation of ATF4 pro-apoptotic target genes PPP1R15A (GADD34) and DDIT3 (CHOP) upon Fluphenazine treatment.