The five factors of the CLL-IPI include the presence or absence of TP53 mutations/del(17p), IGVH mutational status (mutated versus non mutated), serum β2-microglobulin concentration (≤3.5 mg/L vs. >3.5 mg/L), clinical stage (Binet A or Rai 0 vs. Binet B–C or Rai I–IV) and age (≤65 years vs. >65 years) [38]. Here, TP53 is linked to B-cell chronic lymphocytic leukemia.