CD4 and rheumatoid arthritis: As expected, CD4 proliferation towards adalimumab peptides (Figure 1A, left) was much less than to tetanus toxoid, as the latter contains a multitude of epitopes, but CD4 T cell responses exceeding the mean proliferation + 3*SD of control wells (no peptide) could still be detected against several adalimumab-specific peptides in RA patients (Figures 1B, 2A).