IL-18 has been implicated in various inflammatory skin diseases, including psoriasis, atopic dermatitis (AD), urticaria, contact dermatitis, alopecia areata (AA), drug allergy, graft-versus-host disease (GVHD), cutaneous lupus erythematosus (CLE), and etc. [18,20,21,22,23]. The gene discussed is IL18; the disease is Alzheimer disease.