Studies of leukaemic cells suggest that IL1RAP may promote FLT3 and cKit signalling,23 with potential implications for haematopoiesis, dendritic cell homeostasis, and atherosclerosis.24 However, IL1RAP-deficient mice displayed normal haematopoiesis,25 arguing against a role for IL1RAP in modulating cKit signalling in non-leukaemic cells. Here, FLT3 is linked to atherosclerosis.