Using this highly sensitive digital immunoassay, this study investigated the ability of serum IFN-α2 levels to discern jSLE patients from controls [juvenile idiopathic arthritis (JIA) patients and healthy participants], and jSLE patients with active disease from those in a low disease activity state (LDAS) and/or remission [15–18]. The gene discussed is IFNA2; the disease is juvenile idiopathic arthritis.