CD4 and rheumatoid arthritis: Our data are in agreement with previous reports, showing increased levels (percentages and absolute numbers) of total Th17 (defined as CD4+IL-17+) and pTh17 cells (defined in this study as CD4+CD183+IL-17+IL-22+CD243+CD161+IFN-γ+IL-10−) in patients with RA [3, 6–9].