Previous reports identified relatively high serum levels of sCTLA-4 in SLE patients [20, 21], but that work used antibodies capable of binding either native sCTLA-4, exocytosed full-length CTLA-4, or fragments of the extracellular domain of CTLA-4 cleaved from the cell surface. The gene discussed is CTLA4; the disease is systemic lupus erythematosus.