IL33 and systemic sclerosis: Furthermore, skin-resident Tregs from patients with systemic sclerosis are differentiated into Th2-like Tregs, which produce a higher amount of IL-4 and IL-13, by high expression of skin-localized IL-33, suggesting that IL-33 might be an important factor that contributes to fibrosis due to loss of normal skin-localized Tregs function (98).