IL17A and infection: In addition, IL‐23/IL‐17 blockade is associated with some side effects, e.g. increasing susceptibility to infections and unpredictable immune shift caused by the disrupted cytokine networks.[37] Compared to the above clinically used biologic therapies, nor@MSC‐EVs could potentially avoid the overactive immune system and achieve complete healing of psoriasis by combined modulation of both metabolic and immunological disorders in psoriasis.