Used in pharmaceutical research as a potent and selective inhibitor of Janus kinase 1 (JAK1), showing promise in the treatment of autoimmune and inflammatory diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease. Its high selectivity for JAK1 over other JAK family members may reduce off-target effects and improve safety profiles in long-term therapy. Currently investigated in clinical trials for oral administration due to good bioavailability and metabolic stability.