IL4 and systemic sclerosis: In the dermis of SSc patients, accumulation of immune cells including macrophages, B and T cells, and DCs have been reported, which produce different kinds of pro-inflammatory (TNF-α, IL-1, IL-6, and IL-2) and pro-fibrotic (IL-4, IL-13, IL-6, and TGF-β) cytokines (76) and different autoantibodies (77, 78).