TRAV26-1 and rheumatoid arthritis: In the PBMC of RA donors, we obtained one TCR using the HLA-DR4Vim-64cit59-71 tetramer and three TCRs with the HLA-DR4α-eno-15cit10-22 tetramer, where all four TCRs showed TRAV26-1 gene usage across different epitopes.