ISG15 and peeling skin syndrome: Furthermore, the expression levels of type I interferon signaling pathway-related genes including ISG15, RSAD2, IFI6, IFIT2, MX1, OAS3, IFIT1, IFIT3, IFIT5, IRF7, OAS2, STAT2, XAF1, OASL, ZBP1, IFI35, IFITM3, BST2, SOCS1, USP18, IFI27, and TRIM6 were upregulated (Fig. 3A, Table S3), and the hierarchical clustering heatmap of these genes is shown in Fig. 3B. We then enrolled another 18 pSS patients and 16 age and sex-matched HCs and performed RT-PCR to confirm the upregulated type I interferon-related gene expression in neutrophils of pSS patients.