The expression levels of serum IL‐22, IL‐1RA, and IL‐10 in patients with moderate to severe psoriasis were lower than normal, and the decreased level of IL‐22 was significantly different compared with normal subjects (p < 0.01) (Table 1, Figures 1, 2, 3, 4, 5, 6). Here, IL22 is linked to psoriasis.