Prognosis of CLL patients has historically been determined by categorization into Rai or Binet risk groups based on physical examination and blood counts, however given heterogeneity within Rai or Binet risk categories, these prognostic tools have limitations predicting clinical course and response to therapy. More recently, the CLL-international prognostic index (CLL-IPI) discriminates four prognostic subgroups based on five independent clinical, biochemical, genetic and molecular prognostic factors including age, clinical stage, IGHV mutation status, serum β2-microglobulin concentration and TP53 deletion and/or mutation, in an attempt to improve prognostication and to allow more targeted management of CLL patients [1 International CLL-IPI working group. An international prognostic index for patients with chronic lymphocytic leukaemia (CLL-IPI): a meta-analysis of individual patient data. Lancet Oncol. 2016;17:779–790. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] ].