Donal McLornan, MB BCh, MRCP, PhD, FRCPath, Guy’s and St Thomas’ NHS Foundation Trust, London, UK, discusses upcoming work on unclassifiable myeloproliferative neoplasms (MPNs) at the American Society of Hematology (ASH) Annual Meeting and Exposition 2019. This is a retrospective study by the European Society for Blood and Marrow Transplantation (EBMT) Chronic Malignancies Working Party on the outcome of allo-HSCT in MPNs-unclassifiable.This interview took place at the MPN Advances Day 2019 in London, UK.