B cell lymphoma 6 protein (Bcl-6) proto-oncogene product (a Kruppel-type zinc-finger protein) is mainly expressed in normal germinal center B cells and related lymphomas Bcl-6 is involved in chromosome rearrangements at 3q27 in non-Hodgkin’s lymphomas and Bcl-6 rearrangements have been detected in 33%-45% of diffuse large B cell lymphomas