BCL2 and B-cell chronic lymphocytic leukemia: In a previous study, using a cDNA-based microarray approach to characterise expression of apoptosis-regulating genes in B-CLL, we found the antiapoptotic bcl-2 family member bfl-1 as the most discriminating gene between untreated patients whose leukaemic cells were sensitive to in vitro fludarabine-induced apoptosis and chemotherapy refractory patients with in vitro fludarabine-resistant leukaemic cells (Morales et al, 2005).