IRF5 is a transcription factor that serves as a critical mediator of innate immune responses, particularly downstream of endolysosomal toll-like receptors (TLR7, TLR8, TLR9) 1. It activates transcription of type I interferons (IFN-α and IFN-β) and inflammatory cytokines by binding interferon-stimulated response elements (ISRE) in gene promoters 1. IRF5 activation occurs through the SLC15A4-TASL adaptor complex, which recruits and activates IRF5 via a conserved pLxIS motif 1. IL-10 suppresses IRF5 activity through epigenetic mechanisms, downregulating chr7 accessibility and interferon-stimulated genes 2. IRF5 dysregulation is implicated in systemic lupus erythematosus (SLE), where aberrant IRF5 hyperactivation occurs in both active and remission phases 34. Genetic variations in IRF5 associate with SLE risk, and IRF5 hyperactivation correlates with disease severity markers including anti-dsDNA titers 4. Pharmacological IRF5 inhibition and selective kinase inhibitors targeting the TBK1-IRF5 axis suppress lupus pathology, reduce autoantibody production, and improve survival in preclinical models 345. These findings establish IRF5 as a therapeutic target for SLE and suggest IRF5 inhibitors may overcome limitations of current immunosuppressive therapies.