There is overwhelming evidence that IKZF1 variants are associated with childhood acute lymphoblastic leukaemia [33], [34] and several diseases with an autoimmune component: systemic lupus erythematosus (SLE) [35]–[37], type 1 diabetes [38], [39], Crohn's disease [40], systemic sclerosis [41], malaria [42] and erythrocyte mean corpuscular volume [43] (Table 2). The gene discussed is IKZF1; the disease is Crohn disease.