Upilumab, an IL-4R inhibitor, blocks the Th2 axis in patients with alopecia areata, and these patients showed downregulation of Th2-related markers (CCL13, CCL18, CCL26, CCL24) starting at week 12 of treatment with dupilumab, significant upregulation of the hair keratin gene-set at week 24, and clinical improvement in patients with alopecia areata at week 48 (69). This evidence concerns the gene CCL26 and alopecia areata.