In type 1 diabetes, T-cells are the main contributors to disease pathogenesis and both CD4+ and CD8+ T-cells have been associated with beta cell destruction in non-obese diabetic (NOD) mice14, with e.g. CD4+ T-cells recruiting macrophages and natural killer cells to the pancreatic islets15,16. The gene discussed is CD4; the disease is type 1 diabetes mellitus.