Knock-down of pXbp1 increased ER stress-induced cell death and down-regulated expression of target genes. (A) Cell viability of TM treated PEF cells was decreased by the knock-down of pXbp1 (open square) compared with the control siRNA (square). Data are presented as means ± SEM. *P < 0.05. (B) Knock-down of pXbp1 decreased expression of ERdj4, p58IPK, BiP, CHOP, and GRP94 target genes in the TM treated and non- treated PEF cells. β-actin was used as the loading control.