Induced expression of ΔN-IκBα in double-transgenic mice injected with mifepristone. (a) Schematic of the inducible transgenic mouse system used. (b) Mifepristone dose–dependent expression. Mice were killed 3 hours after intraperitoneal injection of the indicated dose of mifepristone dissolved in sesame oil. Western blot analysis of liver protein lysates was performed using an antibody to either the C terminus of IκBα (top panel) or to the FLAG epitope (bottom panel). Lanes represent individual animals. (c) Timing of induced expression. Mice were killed at the indicated times after injection of 5 mg/kg mifepristone. (d) Liver-specific expression of ΔN-IκBα. Organs were harvested from a mouse killed 3 hours after injection with 5 mg/kg mifepristone. Western blot analysis was performed using an antibody to IκBα (top panel) or FLAG (bottom panel).