Consistent with the effect of OZ on the UPR, PERK or IRE1 inhibition did not alter its effect, whereas ER stress inducers, such as tunicamycin or nelfinavir, or an inhibitor of eIF2α dephosphorylation enhanced the growth-inhibitory effects of OZ in HCC cells. The gene discussed is EIF2AK3; the disease is hepatocellular carcinoma.