Phase microscopy images of day 5 ODN + IL15-stimulated CLL cultures, receiving a 24 pulse with YM155 (333 nM) or vehicle alone prior to observation (Figure 3) reveal that exposure to YM155 elicits shrunken cells with fragmented nuclei and membrane blebs, consistent with apoptosis (Figure 3B). The gene discussed is IL15; the disease is B-cell chronic lymphocytic leukemia.