Bcl-2 does not prevent upregulation of IκB protein by Dex. Parental and bcl-2 ARP-1 transfectants were treated with and without Dex (0.1 μmol/L) for different times. WCEs were prepared and assayed for IκB protein expression by Western blotting. WCE from HeLa cell line was used as a positive control for IκB protein expression. IκB and NS, a nonspecific cross-reacting protein, are indicated by arrows.