Although the role of NFAT5 in high salt-induced development of TH17 cells in autoimmune diseases remains elusive, it is conceivable that tonicity-dependent NFAT5 activation has a pivotal role in initiating RA in smokers, who often enjoy eating salty food because it is crucial to both high salt-induced activation of TH17 cells (56) and osmo-protection (57). Here, NFAT5 is linked to rheumatoid arthritis.