Stem cell-derived EVs are emerging as safe, immunomodulatory candidates for psoriasis, capable of attenuating IL-23/JAK–STAT and IL-17/NF-κB signaling and rebalancing the Treg/Th17 axis; they may function as a monotherapy or as adjuncts that enhance efficacy and reduce toxicity of existing regimens. The gene discussed is IL17A; the disease is psoriasis.