Hughes, T.; Kim-Howard, X.; Kelly, J.A.; Kaufman, K.M.; Langefeld, C.D.; Ziegler, J.; Sanchez, E.; Kimberly, R.P.; Edberg, J.C.; Ramsey-Goldman, R.; et al. Fine-mapping and transethnic genotyping establish IL2/IL21 genetic association with lupus and localize this genetic effect to IL21. The gene discussed is IL21; the disease is systemic lupus erythematosus.