SMAD4 and psoriasis: Adheres junction, Hedgehog signaling pathway and Cell cycle pathway (Supplementary Figure 1) were highlighted in our data, indicating that psoriasis epidermal cells are over-proliferated with skin barrier dysfunction, which may be attributed to a group of down-regulated proteins, including vinexin, Smad4, FERM, metastasis suppressor protein 1 and catenin delta-2 as shown in our data.