BLK and peeling skin syndrome: Identified susceptibility genes include interferon regulatory factor 5 (IRF5), signal transducer and activator of transcription 4 (STAT4) and IL-12A, all participating in IFN signaling; B-lymphocyte kinase (BLK) and chemokine receptor 5 (CXCR5), which are important for B-cell function and antibody production and clearance, and the TNPIP1 gene that is involved in the negative regulation of NF-κΒ pathway.19 Genetic regulatory mechanisms are also of emerging interest in the pathogenesis of PSS, with abnormalities observed in DNA methylation and microRNAs.20