TGF-β, but not IL-6, induces CD133 expression in a stable fashion. a. Experimental design is indicated in the upper panel. Huh7 and HepG2 cells were grown in control culture conditions (depicted in gray text and lines), or exposed to 10 ng/ml IL-6 (red) or 10 ng/ml TGF-β (blue) for 4 days. Cells plated in parallel, had their medium replaced by control culture medium and were left in culture for additional 4 days. FACS expression of surface CD133 protein is shown for day 0, day 4, and day 8 (4 days treatment + 4 days post-release) for all conditions, in logarithmic scale. Histograms are shown for one representative replicate in the middle panel. Mean +/- SD is shown for three biological replicates in the lower panel barplots. b. TGF-β type I receptor antagonist SB 431542 was used at 2uM, alone or in combination with 10 ng/ml of TGF-β, and DMSO used as control. CD133 expression was studied by FACS after 4 consecutive days of exposure to each experimental condition. (*) indicates P value < 0.05 relative to all other conditions, for both cell lines. Representative phase contrast images are shown in the lower panels.