This study characterized a new signalling pathway in nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-triggered lymphoma. The authors showed that the transcription factors JUN and JUNB promote lymphoma development and tumour dissemination through transcriptional regulation of platelet-derived growth factor receptor B (PDGFRB). Inhibition of PDGFRB with imatinib prolonged the survival of NPM-ALK transgenic mice and increased the efficacy of the ALK-specific inhibitor crizotinib in transplanted NPM-ALK tumours. In a patient with refractory late-stage NPM-ALK-positive lymphoma, imatinib produced a rapid, complete and sustained remission.