Apoptosis in B-chronic lymphocytic leukaemia

B-chronic lymphocytic leukaemia (B-CLL) is characterised by the progressive accumulation of monoclonal B cells, which may be the result of several fac tors leading to extended B-CLL cell lifespan, increased proliferative capac ity and diminished cell death. Here we review the implications of several s ignals mediated by receptors, such as surface IgM, CD6 and CD40, for the B- CLL cell survival, together with data on gene modulation in relation to the apoptosis process in B-CLL cells. We also describe some features of the Fa s/FasL system in B-CLL that hypothetically might contribute to the accumula tion of leukaemic cells and the progression of the disease, by downregulati ng the apoptotic response or avoiding the autologous immune response.