Re-evaluation of the distinction between type I and type II cells: the necessary role of the mitochondria in both the extrinsic and intrinsic signaling pathways upon Fas receptor activation.

Cyclosporin A (CyA) and bongkrekic acid (BK) prevented Fas-induced apoptosis in two type I cell lines (H9 and SKW6.4) and two type II cell lines (Jurkat and CEM). CyA and BK inhibited the release of cytochrome c in all four cell lines.