HMGB1 and rheumatoid arthritis: In the present study, we found that in RA patients, the mRNAs of HMGB1, RORγt, and IL-17 in PBMCs and the levels of HMGB1, IL-17, and IL-23 in plasma were increased, and there was a positive correlation between HMGB1- and Th17-cell, especially in active phase of RA.