JAK2 and COVID-19: Different JAK inhibitors have been proposed for the treatment of COVID-19, namely: JAK1/JAK2/TYK2 inhibitors (e.g., baricitinib, ruxolitinib) (103–109), selective JAK2 inhibitors (e.g., fedratinib) (110), and - more recently - JAK1/JAK3 inhibitors (e.g., tofacitinib) (111).