Previous meta-analyses have shown significantly elevated serum levels of TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-18, and IL-22 in psoriasis patients, while levels of IL-1β, IL-4, IL-10, IL-12, IL-21, and IL-23 showed no significant differences.5 This evidence concerns the gene IL2 and psoriasis.