IL4 and psoriasis: The JAK/STAT signaling and spleen tyrosine kinase (SYK) pathways are implicated in numerous autoimmune and inflammatory diseases (e.g. AD, psoriasis, alopecia areata) (81), modulating a range of immune responses, including the Th2 (IL-4, IL-13, CCL18), Th1 (IFNγ), and Th17/Th22 (CCL20, S100As) pathways (82).