Proliferation was measured by BrdU incorporation and normalized to untreated cells. Shown are relative ratios (BrdU incorporation of untreated = 1) with mean ± S.E.M. Cells were seeded into 96 well plates and incubated with 10, 50, 100, or 500 μM of bile acid (DC, CDC, GDC and GCDC) for 24 hours. * P < 0.05, ** < 0.01, *** < 0.001, for significantly altered BrdU incorporation. Significance testing was performed with ANOVA and a posthoc t-test.