(A) A549 and H1299 cells were treated with various concentrations of digoxin for 24 h, stained with Annexin V-FITC and PI, and then measured by flow cytometer. (B) Quantification of the apoptotic cells. (C) Western blotting analysis of the indicated proteins in cellular extracts from A549 and H1299 cells treated with various concentrations of digoxin for 24 h. The data are expressed as mean ± SD (n=3). ∗P<0.05, ∗∗∗P<0.01, compared with control.