Dr Ola Landgren from Memorial Sloan Kettering, New York, USA, speaks to the European Medical Journal from the 19th Congress of the European Haematology Association (EHA) meeting about the changed definition of multiple myeloma. A result of a 2-day workshop of the international myeloma working group before the EHA meeting, the definition now includes three additional criteria which are explained. Dr Landgren explores the reason for the altered definition and implications for clinical practice.