In SLE, the monoclonal antibodies belimumab (targeting BAFF) and anifrolumab (targeting the IFN-α/β receptor (IFNAR)) are already being used but cannot relieve all patients from symptoms and complications.4 5 Drugs that target molecules upstream of type I IFN production, and thereby also BAFF production, could be more effective. This evidence concerns the gene TNFSF13B and systemic lupus erythematosus.