TGFB1 and psoriasis: Interestingly, after DMF treatment, Th1 cells were significantly reduced and Treg cells were increased along with downregualted T-bet/IFN-γ and upregulated Foxp3/TGF-β1 level, consistent with previous studies showing that DMF treatment significantly decreased Th1 subset and IFN- γ secretion in patients with multiple sclerosis [32] and induced an increase in the frequency of Treg cells in patients with psoriasis [33].