NOS2 and psoriasis: It would have been useful to assess additional potential biomarkers, identified in nonlesional and lesional skin, and in the blood of patients with atopic dermatitis, including IL-13, IL-22, chemokine (C-C motif) ligand 27/cutaneous T-cell–attracting chemokine CCL27/CTACK (upregulated in atopic dermatitis but downregulated in psoriasis), inducible nitric oxidase synthase 2 (NOS2) (upregulated in psoriasis but downregulated in atopic dermatitis), and CCL17/ thymus and activation-regulated chemokine (TARC)5; however, these biomarkers are not yet readily available in clinical practice.