Activation of PERK and eIF2α signal pathway by RES in Raji and Daudi cells. A, Raji and Daudi cells were incubated with resveratrol (RES; 100 μM) or tunicamycin (Tm; 10 μg/ml) used as a positive control for 8 h and cell lysates were subjected to Western blotting analysis. B, Raji cells were treated with 100 μM of RES for the indicated time, and Western blotting analysis was performed. C, Raji and Daudi cells were incubated with 100 μM of RES or 10 μg/ml of Tm for 8 h and GADD34 mRNA levels were investigated using real-time PCR. D, Cells were treated as C and ATF4 mRNA levels were analyzed. *, P < 0.01.