Tofacitinib is primarily used in the treatment of autoimmune conditions, particularly rheumatoid arthritis. It works by inhibiting the Janus kinase (JAK) enzymes, which play a crucial role in the immune response and inflammation. This makes it effective in reducing joint pain, swelling, and stiffness in patients with moderate to severe rheumatoid arthritis who have not responded well to other treatments like methotrexate. In addition to rheumatoid arthritis, tofacitinib is also approved for the treatment of psoriatic arthritis, a condition that affects some people with psoriasis, causing joint pain and swelling. It helps in managing the symptoms and improving physical function in these patients. Another significant application of tofacitinib is in the treatment of ulcerative colitis, a chronic inflammatory bowel disease. It is used for patients who have not responded adequately to other therapies, helping to induce and maintain remission of the disease. Tofacitinib is also being investigated for its potential use in other autoimmune diseases, such as ankylosing spondylitis and alopecia areata, though these uses are not yet widely approved. Overall, tofacitinib represents an important option for patients with various autoimmune conditions, offering relief from symptoms and improving quality of life.