Delgocitinib, a janus kinase (JAK) inhibitor, is being developed by Japan Tobacco for the treatment of autoimmune disorders and hypersensitivity, including inflammatory skin conditions. The JAK family of tyrosine kinases plays an important role in mediating the biological effects of several inflammatory cytokines, e.g. IL-4, IL-13 and IL-31, which are elevated in patients with atopic dermatitis. Delgocitinib inhibits all members of the JAK family [JAK1, JAK2, JAK3 and tyrosine kinase 2]. Topical delgocitinib (Corectim®) is approved in Japan for the treatment of atopic dermatitis.