HMGB1 and systemic lupus erythematosus: Besides activating T cells and B cells, cDC may also promote lupus development by producing high-mobility group box 1 (HMGB1) protein that not only binds nucleosomes to facilitate activation of cDC as a positive feedback but also enhances IFNα production by pDC, the latter of which will be discussed below [46, 49, 84].