Janus tyrosine kinase (JAK) signaling may be involved in the pathogenesis of polymyalgia rheumatica (PMR), and tofacitinib may be an effective treatment, according to a pilot study. Xinlei Ma and colleagues examined pathogenetic features of PMR and assessed the efficacy and safety of the JAK inhibitor tofacitinib in patients with PMR. The analysis included 11 treatment-naive PMR patients and 20 healthy controls. In a second cohort, 76 patients with PMR were randomly assigned to tofacitinib or glucocorticoid treatment in an open-label trial, with 67 completing the 24-week intervention. The researchers found that gene expression patterns of peripheral blood mononuclear cells...