These results suggest that an increased proportion of Treg cells promotes the pathogenetic process of lung fibrogenesis (50, 51), and the main reason for the opposite results in the above two aspects is that (52–55): the role of Treg cells in the progression of lung fibrosis depends on the disease progression, For example, Treg cells may mediate TGF-β1 production and collagen accumulation in the early stage but may attenuate silicosis in mice in the late stage (52). The gene discussed is TGFB1; the disease is pulmonary fibrosis.