JAK2 and rheumatoid arthritis: Noteworthy, in 2021, the FDA alerted the public to the heightened risk of severe heart-related incidents, blood clot formation, and death linked to the use of JAK inhibitors, including tofacitinib, upadacitinib, and baricitinib (a JAK1 and JAK2 selective inhibitor approved for the therapy of rheumatoid arthritis (RA)), based on the outcomes of the ORAL clinical trial of tofacitinib in patients with RA.