To investigate the net effect of eIF2α–ATF4 pathway activity on hepatoma cell susceptibility to proteasome inhibition, we first determined the concentration of bortezomib to induce ~50% cell death after 24 h (Figure 1A) and then combined bortezomib treatment with pharmacological compounds that specifically augment or neutralize eIF2α phosphorylation [8] (Figure 1B). Here, EIF2A is linked to hepatocellular carcinoma.