A. Inhibitory effect of DSF (0.5 μM), Cu (1 μM) and DSF/Cu (0.5/1 μM) on the ALDH-positive cell population from the NSCLC cells lines H1299 and H460. B. DSF (0.1 μM, and 0.5 μM) and DSF/Cu (0.1/1 μM, and 0.5/1 μM) inhibit the expression of the stem cell transcription factors Nanog, Sox2 and Oct-4 expression in H1299 cells. C. Inhibitory effect of DSF (0.5 μM), Cu (1 μM) and DSF/Cu (0.5/1 μM) on the colony forming ability of H1299 cells (*P < 0.05, **P < 0.01, ##P < 0.01, one-way ANOVA). D. Inhibitory effect of DSF and DSF/Cu on tumorsphere formation. Tumorspheres were incubated with DSF (0.5 μM), Cu (1 μM) and DSF/Cu (0.5/1 μM) for 7 days. Scale bar, 100 μm. (**P < 0.01, ***P < 0.001, one-way ANOVA). E. Inhibitory effect of DSF/Cu on transwell invasion assay. Cells were incubated with DSF (0.5 μM), Cu (0.5 μM) and DSF/Cu (0.1/0.5 μM, 0.25/0.5 μM and 0.5/0.5 μM) in transwells for 24 hours (*P < 0.05, **P < 0.01, one-way ANOVA).