GA induces ER stress via up-regulation of GRP78, CHOP, ERdj4 and GADD34 mRNA. HeLa cells were treated with 10 μg/ml of tunicamycin (Tm) or 0.3 μg/ml of GA for 0, 4 and 8 h. Cells were collected and mRNA was extracted and evaluated by real-time RT-PCR. Each mRNA was normalized with the mRNA of GAPDH. Data are the results of three independent experiments, expressed as the mean ± SD, n = 3. *p < 0.05; **p < 0.01 shows significant difference compared with 0 h; #p < 0.05, is significantly different as compared between 4 h and 8 h.