Fig. 3. CDDO and ara-C induce release of cytochrome c. U-937 and U-937/Bcl-xL cells were treated with 5 µM CDDO (A) or 10 µM ara-C (B) and harvested at the indicated times, respectively. Cytosolic lysates were analyzed by immunoblotting with anti-cytochrome c. IB, immunoblot; Cyt c, cytochrome c.