Moreover, based on reports demonstrating that high levels of TNFR1, but not TNFR2 are detected on CD4+ T lymphocytes that migrate to rheumatoid synovium [51], it would be interesting to analyze the expression of TNF-α receptors on Th1 and Th17 cells infiltrating the synovia of RA patients before and after therapeutic intervention with TNF-α inhibitors. Here, CD4 is linked to rheumatoid arthritis.