Graham Collins, MA, MBBS, MRCP, FRCPath, DPhil, from the Oxford University Hospitals NHS Foundation Trust, Oxford, UK discusses difficult to treat indolent hematological disease patient groups at the 2017 British Society for Haematology (BSH) Annual Scientific Meeting in Brighton, UK. He introduces groups in which treatment is still a challenge, including follicular lymphoma patients who progress within two years of CHOP chemotherapy, as well as the group of patients who progress soon after treatment with anti-CD20 and alkylating agent therapy. He also speaks about the GADOLIN trial (NCT01059630) in rituximab-refractory indolent non-Hodgkin lymphoma (NHL), as well as the potential of stem cell transplantation after treatment in these patient groups.