NFAT5 or tonicity enhancer binding protein (TonEBP) is a calcineurin-independent member of the Rel family of transcription factors and has recently been described as an immunometabolic stress protein that modifies the cellular transcriptome in a plethora of pathophysiological conditions including hyperlipidemia, insulin resistance, arteriosclerosis, rheumatoid arthritis, hypertonicity [7,8], and ischemia [9]. This evidence concerns the gene NFAT5 and rheumatoid arthritis.