Induction of phosphorylation of eIF2α with tunicamycin in an EBV-positive cell line, 721, leads to an increase in LMP1 protein levels. Cells of an EBV-positive cell line, 721, were treated with 2.5 μg/mL tunicamycin, harvested at 0, 4, 8, 12, 36, and 48 hours, and analyzed by Western blotting using antibodies to detect LMP1, phosphorylated eIF2α, total eIF2α, and tubulin. The top numbers represent the fold-difference of ratios of phosphorylation of eIF2α after tunicamycin treatment relative to 0 hours. The bottom numbers represent the fold-difference of ratios of LMP1 to tubulin after tunicamycin treatment relative to 0 hours. *P (2-sided) <.05, Wilcoxon signed rank test. A representative gel of 3 independent experiments is shown.