Effects of additives on the activity of a transfected fibin-promoter construct. L929 cells and HEK293 cells were transfected with the 2.5-kbp-fibin promoter construct. After 24 h, 10 μM dexamethasone, 10 μM phorbol ester, and 300 μM MnCl2 were added. Cells were lysed after the indicated time of incubation and luciferase activity was measured. Results (controls: white bars; compounds: grey bars) are shown as means of relative luciferase activity ± SEM of four (L929 cells) and three (HEK293 cells) experiments. Significant differences between sample and control conditions are marked with *p < 0.05, **p < 0.01, ***p < 0.001 using the Student's unpaired t-test.