Figure 2 TRIB3 is induced by cell stress and is expressed in hypoxic areas. (a) Fold induction of TRIB3 mRNA expression (mean + standard deviation (SD)) after 24 hours incubation with hypoxia mimetic (CoCl2, inhibitor of the degradation of HIF-1, see insert), anoxia (oxyrase), estrogen receptor (ER) stress (thapsigargin) or nutrient starvation in the ER positive MCF7 and the ER negative MDA-MB-231 cell lines. Each measurement was performed at least in triplicate. (b) Fold induction of TRIB3 mRNA expression (mean + SD) after incubation of MDA-MB-231 cells at increasing oxygen concentrations (oxyrase (~0%), 0.1%, 0.2% and 0.5% oxygen) compared with normoxia. Each measurement was performed at least in triplicate. (c) Triple fluorescent staining in two different xenografts of MDA-MB-231 cells for TRIB3 (red), pimonidazole (green), and 9F1 (blue) showing colocalization of TRB3 and hypoxia, distal from blood vessels.