Survival of CLL patients structured according to the TP53 defects, ATM deletion, and mutation status of IgVH. Survival was analyzed from time of TP53/ATM investigation. An effect of the abnormalities on survival was assessed in comparison with p53-wt/ATM-wt subgroup harboring the unmutated IgVH (curve D). Biallelic TP53 changes showed strong effect (P < .001), monoallelic TP53 abnormalities intermediate effect (P = .021), and ATM deletion no impact at all (P = .55).