TP53 and B-cell chronic lymphocytic leukemia: According to most practice guidelines today, TP53 disruption remains the lone predictive biomarker in CLL [38,39,40,41] and should be analyzed prior to treatment initiation in all patients owing to the large body of evidence demonstrating that patients either do not respond to initial chemoimmunotherapy (CIT) or experience relapse soon after remission [42] (Table 2).