CD4 and rheumatoid arthritis: This included T cell subsets (αβ T cells, γδ T cells, CD4/CD8, naïve, central memory, effector memory, terminal effector memory expressing RA (TEMRA) T cells, T-follicular helper (Tfh) cells, Th subsets (Th1, Th2, Th17, Th1/17), exhausted T cells, regulatory T cells (Tregs)), B cell subsets (transitional, naïve, memory, unswitched memory, plasmablasts and plasma cells, atypical B cells, κ-light chain vs. λ-light chain usage) and NK cells.