In summary, IL-23p19 blockade by guselkumab in patients with psoriasis (vs TNF-α blockade by ADA) more dramatically reduced serum concentrations of cytokines IL-17A, IL-17F, and IL-22, which are associated with the IL-23/IL-17 pathway, thereby limiting the downstream activity of these effector inflammatory cytokines. This evidence concerns the gene IL23A and psoriasis.