JAK1 and mucous membrane pemphigoid: Abrocitinib is an orally active selective JAK1 inhibitor that effectively treats some autoimmune diseases, including atopic dermatitis and mucous membrane pemphigoid.[54, 55] In this study, abrocitinib effectively attenuated radiation‐induced injuries in the BBB MPS, indicating the vital role of type I IFN and the downstream JAK/STAT signaling pathway in disease pathogenesis.