BCL2A1 and juvenile idiopathic arthritis: Compared to PBMC/SFMC samples and non-arthritic biopsies, naïve and memory B cells expressing germinal center (GC) markers such as BCL2A1 and CD83 were enriched in JIA tissue (IgD+ GC-like B and GC-like memory B cells), suggesting the acquisition of this cell state upon entering the inflamed tissue microenvironment (Fig. 3C, fig.