Thus this rearrangement appears to be very rare in B-CLL and its finding should lead to a careful search for the characteristic features of MZL, namely, morphology, the expression of CD5 without CD23, high density monotypic SIg, together with t(11;14) and/or bcl-1/IgH rearrangement.
Although initial reports on small panels of cases had suggested a role for Bcl-1 and Bcl-2 oncogene activation in B-CLL, later investigations failed to confirm these data.