IRF5-CPP5 is a cytosolic peptide that selectively targeting human IRF5 wirh a Kd of 0.53 µM. IRF5-CPP5 disrupts IRF5 homodimerization and inhibits its nuclear translocation without altering IRF5 phosphorylation levels. IRF5-CPP5 inhibits proinflammatory cytokine (IL-6, IL-1beta, TNF-alpha) production. IRF5-CPP5 can be used for the research of systemic lupus erythematosus[1].