CD28 and inflammatory skin disease: We found that 55 DEGs (including CD28, CD48, CD53, ID4, IL37, IL4R, IL7R, JAK3, KRT16, KRT6A, PI3, S100A7, S100A8, S100A9, SERPINB3, SERPINB4, and UPP1) are common in seven inflammatory skin diseases, except irritant contact dermatitis (ignored due to significantly a smaller number of DEGs reported) (Fig. 2C, Table S1).