Oba MC, Askin O, Ekmekci OB, et al. - Researchers conducted this single-center prospective study to compare serum granulysin levels in patients with alopecia areata (AA) before and after therapy and to investigate the association between serum granulysin levels and disease severity. The Severity of Alopecia Tool (SALT) score and serum granulysin levels of 38 AA patients were evaluated at baseline and at 6 months of therapy. For this analysis, 33 patients were treated with tofacitinib 5 mg BID, and five patients were treated with topical immunotherapy. A moderate correlation between SALT scores and serum granulysin level at baseline was found. Compared with patients with patchy AA, baseline serum granulysin levels were significantly higher in patients with alopecia totalis/universalis. The results suggest that serum granulysin levels correlate well with AA immunological activity. Granulysin is also assumed to be a potential mediator of a follicle attack, the effects of which are blocked by tofacitinib therapy. Changes in serum granulysin levels under treatment can therefore reflect downregulation of AA immunological activity.