Transmembrane activator and CAML interactor (TACI) was identified as a receptor for BAFF and APRIL, two members of TNF ligand family. The significantly lower TACI expression on B cells from CLL patients than from normal controls raised the question of the importance of TACI in CLL pathogenesis. We investigated the relationship between TACI expression and pro- and antiapoptotic proteins expression in CLL cells. Moreover, we were interested in a possible relationship between TACI expression and prognostic factors such as: CD38 antigen or ZAP-70 protein expression, which are known poor prognosis factors in B-CLL. Our results confirm the significance of apoptosis deregulation in CLL and suggest the possible relationship between TACI expression and the clinical course of the disease.