TNF and psoriasis: Interestingly, when we re-analyzed the expression levels of known psoriasis-associated cytokines in previously published data sets, comparing gene expression of skin lesions to non-lesional controls derived from the same patient, IL36A, IL36B, and IL36G displayed the most significant increase in expression compared to conventional cytokines such as IL17A, IL23A or TNF (Figure 1B) (28, 29).