Although IL-7Rα is expressed mainly by lymphocytes and innate lymphoid cells, such as NK cells (20, 21), expression of IL-7Rα is elevated in the synovial tissues and macrophages from RA synovial fluid compared with macrophages from healthy controls, undifferentiated arthritis patients, and osteoarthritis patients (22, 23). Here, IL7R is linked to rheumatoid arthritis.