H19 and rheumatoid arthritis: LncRNA H19, FAM66C, Hotair, lincRNA‐p21, C5T1, LOC100652951, and LOC100506036 have been found to be dysregulated in T cells, PBMCs, and synovial cells, or exosomes isolated from patients with RA, and the abnormal expression of lncRNAs in T cells can promote or suppress immune‐mediated inflammation in RA.21