Loss of mitochondria integrity with KRN5500 treatment of B-CLL cells. After 24 hours of incubation without (A) or with (B) KRN5500, cells were incubated with 50 nM rhodamine-123 and then analyzed by flow cytometry. The rise in the lower intensity peak, with KRN5500 treatment, indicates loss of the fluorescent dye rhodamine-123 from mitochondria.