IL17A and Arthritis: Of notice, numbers of total T cells (TCRβ+ cells) and CD4+ T cells and of total cTregs and RORγt-expressing cTregs — but not of CD4+IL-17+FoxP3– (cTh17) cells — were expanded in the colons of mice with established versus early DSS-induced arthritis (Supplemental Figure 5, E–H).