At least half of all tumors lose WT p53 function as a result of mutations [29], however a subset of tumors, such as cervical cancer, chronic lymphocytic leukaemia, acute lymphoblastic leukaemia, acute myeloblastic leukaemia, myeloma, neuroblastoma, melanoma, mantle cell lymphoma and sarcoma, retains WT p53, but its activity can be attenuated [30, 31]. The gene discussed is TP53; the disease is B-cell chronic lymphocytic leukemia.