Such “treatment-resistant” cases are rare according to a recent review by Orzan et al.4 The most thorough review regarding new-onset IBD after treatment with IL-17 inhibitors, has been provided by Deng et al. In this retrospective study, 34 cases were included, most of which (91%) reported diarrhoea as the prevailing symptom. The gene discussed is IL17A; the disease is inflammatory bowel disease.