CXCR5 and systemic lupus erythematosus: Here, we identified an imbalanced profile of Tfh cell subsets in SLE, including the newly described anti-inflammatory CXCR5+PD-1lowTreg, CXCR5+PD-1highTreg, and the pro-inflammatory Tfh and Tfh17 and investigated the change of these subtypes by low-dose IL-2 treatment in a randomized, double-blind, placebo-controlled study in SLE.