Based on experimental and preclinical data, the oral selective JAK1 and JAK2 inhibitor baricitinib (which has been approved for the treatment of RA) was recently studied in 314 patients with epidural SLE, an epidural disease primarily involving the skin and joints, in a randomized, 24-week, placebo-controlled phase II trial (57). This evidence concerns the gene JAK2 and rheumatoid arthritis.