The half-time of Nrf2 in SW1990/Gem and Panc-1/Gem cells was detected by CHX-chase analysis. SW1990/Gem and Panc-1/Gem cells were pre-treated with or without 80 nM of digoxin for 6 h. Subsequently, cells were incubated with 25 μM of cycloheximide. Total cell extracts were prepared at indicated time point after following treatment with cycloheximide, and then cell extracts were detected by western blot. Image J software was used to quantify the intensity of the bands.