VIM and rheumatoid arthritis: We assessed the frequency of DRB1*04:01 restricted T cells specific for citrullinated epitopes  to which immune responses were previously shown to be present in patients with established RA, including citrullinated (cit) forms of aggrecan29, CILP (isoform 1)15, vimentin and fibrinogen15, and α-enolase30, as well as T cells specific for an influenza peptide as an experimental control.