Many immune cells, including B cells, CD8+ T cells, natural killer (NK) cells, express IL-2Rs at various levels.26 Endothelial cells and smooth muscle cells were also reported to express IL-2Rs.27,28 The effects of LD-IL-2 on these IL-2Rs–expressing cells might also contribute to the clinical efficacy of LD-IL-2 in autoimmune disease treatment. This evidence concerns the gene IL2 and autoimmune disease.