Although the pathogenesis of psoriasis is not fully understood, the immune system is dysregulated by immunogenic stimuli, which activates innate immune cells, resulting in the production of proinflammatory cytokines such as interleukin (IL)-23 and tumor necrosis factor-alpha (TNF-α) and leading to the differentiation of IL-17-secreting T cells2,3. Here, TNF is linked to psoriasis.