Additionally, signal transducer and activator of transcription 4 (STAT4), interferon regulatory factor 5 (IRF5), IRF7, Toll-like receptor 7 (TLR7) and TLR9 are involved in pro-inflammatory cytokine production in monocytes/macrophages and type I interferon (IFN) production by dendritic cells (DCs), which induce and aggravate local and systemic inflammation in SLE (7, 8). Here, IRF5 is linked to systemic lupus erythematosus.