The value of a personalised approach to treatment is increasingly recognised, with the aim of targeting a treatment at the dominant aberrant pathway in a given patient to maximise efficacy and minimise side effects.3 The IL-2 pathway has been identified as potentially therapeutically tractable in numerous autoimmune conditions, including inflammatory bowel disease [IBD], with recruitment to a trial of low-dose IL-2 in CD under way [ClinicalTrials.gov NCT01988506]. The gene discussed is IL2; the disease is inflammatory bowel disease.