FLI1 and systemic sclerosis: In the other model of SSc, mice hetero-deficient in the transcription factor Friend leukemia virus integration 1 (Fli1), it has been reported that the induction rate of Treg cells in the skin at 1 week after the completion of bleomycin administration is lower than that in wild-type mice, which may contribute to the exacerbation of skin fibrosis (86).