IL18 and psoriasis: Furthermore, a recent study found that recombinant mouse (rm) IL-18 synergized with rmIL-23 to induce prominent inflammation, upregulate the levels of IFN-γ and CXCL9, and enhance psoriasis-like epidermal hyperplasia, indicating that IL-18 might cooperate with IL-23 to induce a Th1 immune reaction, thereby aggravating psoriatic inflammation (110).