Even though the first “IFN signature” was defined in subjects with SLE, different sets of ISGs are currently taken into account to classify pathological conditions characterized by a type I IFN dysregulation (i.e. monogenic interferonopathies, dermatomyositis, SLE), to guide molecular diagnostics and to formulate targeted therapy approaches. The gene discussed is IFNA1; the disease is systemic lupus erythematosus.