IL4 and keloid: In addition to the evidence indicating that IL-17-producing Th17 cells stimulate keloid formation, we also found Th2 cells producing IL-4 and IL-13 in the immune infiltrates, which are considered important mediators in the pathogenesis of fibroproliferative diseases such as scleroderma-like cutaneous syndromes (34), abnormal scarring (35) and keloid formation (36).