At the iwNHL 2014, Dr Rafael Fonseca (Mayo Clinic, Arizona, USA) interviews Prof Keith Stewart (Mayo Clinic, Arizona, USA) and Prof Leif Bergsagel (Mayo Clinic, Arizona, USA), all doctors with an interest in myeloma, about the application of myeloma biology and therapies in lymphoma. Prof Stewart describes tumour heterogeneity and suggests a parallel between myeloma and indolent follicular lymphoma, where the presence of a more aggressive tumour subclone may have significant clinical implications. Prof Bergsagel describes the contribution of MYC to tumour heterogeneity and poor prognosis. Targeting the interaction between the immune system and tumour may provide new therapies.