Next, to determine what ligand stimuli could induce potent type I IFN production in psoriasis patients by RIG-I dependent manner, we isolated three psoriasis patients’ PBMCs and stimulated them with one of the four ligands: poly(dA:dT), 5′ppp-dsRNA, plasmid DNAs isolated from E.coli with EndoFree plasmid kits or sonicated salmon sperm DNAs. Here, RIGI is linked to psoriasis.