The expression of TLR7 on circulating precursors of myeloid dendritic cells (pre-mDCs) and mDCs considerably increased in patients with AOSD compared to that of healthy controls (HCs); TLR7 transcription levels correlated with the serum IL-1 and IFN-α levels in AOSD23. This evidence concerns the gene TLR7 and adult-onset Still disease.