IL-23 mRNA level in the inflamed skin was significantly reduced after subcutaneous injection of Sialostatin L, Sialostatin L2, Iristatin, or Mialostatin at the peak of psoriasis (Figure 5D), suggesting a direct connection between the action of tick protease inhibitors on the proteases secreted by the antigen-presenting cells. Here, IL23A is linked to psoriasis.