1. An underlying haematological malignancy including acute myeloid leukaemia in first complete remission (CR1) but with poor prognostic features or in >CR1 or in relapse; acute lymphoblastic leukaemia; transformed myelodysplasia, chronic myeloid leukaemia (accelerated phase or blast transformation, poor response or intolerance of tyrosine kinase inhibitors), myeloma. Patients may be in remission, partial remission or relapse.