Baricitinib, a selective JAK1/JAK2 inhibitor, is approved in several countries for the treatment of moderate-to-severe AD and is recommended in adults who are candidates for systemic therapy.7 It is also approved for the treatment of moderate-to-severe rheumatoid arthritis in adults in Europe, Japan, and the United States, and for the treatment of severe alopecia areata in Japan and the United States. Here, JAK2 is linked to Alzheimer disease.