CX3CR1- and CD103-expressing cells are primarily APC [29, 49, 50] that can capture bacteria from the gut lumen and transport them to the MLN, where they present antigens and activate CD4+ T cells to produce IL-6 that suppresses Treg, which is vital to lupus pathogenesis in lpr mice. This evidence concerns the gene IL6 and systemic lupus erythematosus.