On the cover: In vitro reconstituted human epidermis (RHE) were stimulated or not with IL-22 for 4 days. RHE were fixed, sectioned, and stained with anti-K10 keratin mAb. IL-22 increases the overall thickness of the RHE keratinocyte layer and downregulates keratin 10 expression, supporting an inhibition of epidermal differentiation. Boniface et al. IL-22 inhibits epidermal differentiation and induces proinflammatory gene expression and migration of human keratinocytes. 3695