CD4 and pulmonary fibrosis: Modeling of wild-type mice and TCRδ-/- mice showed that lung fibrosis was more severe in BLM-induced TCRδ-/- mice, which were injected with γδT cells from WT mice, and the number of IL-17A+ CD4+T cells in the lungs of TCRδ-/- mice was lower than that of un intervened TCRδ-/- mice, suggesting that γδT cells reduced pulmonary fibrosis in mice by reducing the number of Th17 cells in the lungs reduced the process of BLM-induced pulmonary fibrosis (84) (Table 1).