JAK1 and rheumatoid arthritis: Upadacitinib is a selective JAK1 inhibitor approved for several autoimmune diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, ulcerative colitis, Crohn’s disease, and moderate-to-severe AD in adults and adolescents aged ≥12 years [28].