IKZF2 and systemic lupus erythematosus: IKZF1, IKZF3 and more recently IKZF2 (Helios) have been identified as susceptibility loci in systemic lupus erythematosus (SLE) in large-scale genome-wide associated studies.8–13IKZF1 polymorphism rs4917014 was identified as a trans-expression quantitative trait locus, driving upregulation of type 1 IFN genes and downregulation of complement genes.14 Ikaros has also been shown to influence TLR7 signalling,15 representing another link with SLE pathogenesis.16