JUNB is involved in sustained gastrin induced expression of ER stress/UPR related genes. Cells with JUNB knocked down (JUNB KD) and control cells (Firefly KD) were harvested at indicated time points after sustained gastrin treatment, and mRNA expression level for selected genes were measured by qRT-PCR analysis. Results show fold induction of gastrin treated cells relative to untreated control cells (mean +/− SD of three technical replicates). The mRNA expression level of Atf4 was 57% lower in JUNB KD cells compared to control cells at 4 h. Herpud1 mRNA levels were ~30% lower in JUNB KD cells at 1, 2 and 4 h, while Chac1 was repressed 58% and 45% at 2 and 4 h, respectively when JUNB was knocked down. Figures represent one of two independent experiments.