Cytokine and chemokine levels, alone or combined with other circulating markers, might be used as follow-up markers: in a recent study of German patients with AE, the spontaneous cellular release of pro-inflammatory IL-31 and IL-33 was clearly depressed in all AE patients, while regulatory IL-27, anti-inflammatory SDF-1/CXCL12, and eosinophil granulocyte attracting Eotaxin-1, Eotaxin-2, and Eotaxin-3 (CCL11, CCL24, CCL26) were enhanced with disease progression [25]. The gene discussed is CCL26; the disease is acrodermatitis enteropathica.