NF-κB inactivation causes massive spontaneous apoptosis.

(A) Annexin staining was performed with Ad5-control– and Ad5-IκBΔN–infected cells at the indicated time points (see “Materials and methods”). (B) Caspase-3 expression. Whole-cell extracts of noninfected and infected L428 cells were prepared at the indicated time points and analyzed by Western blotting. NI indicates noninfected.