BCL6 and cancer: A subset of BTB/POZ proteins have been implicated in human cancer, and they include BCL-6 (B-cell lymphoma 6) [6-9], PLZF (promyelocytic leukemia zinc finger) [10-14], leukemia/lymphoma-related factor (LRF)/Pokemon [15-18], HIC-1 (hypermethylated in cancer-1) [19-23], NAC-1[24-29] and Kaiso [30-33].