CD8A and rheumatoid arthritis: The hallmark of RA-associated inflammation is the recruitment of a variety of immune cells, including neutrophils, monocytes/macrophages, B lymphocytes (B cells), and CD4+ and CD8+ T lymphocytes (T cells) to the synovial compartment, where pro-inflammatory cytokines and chemokines are produced, together contributing to the pathogenesis of RA (3–5).