However, no direct study identified this until Yang et al. [63] reported in 2019 that the expression of IL-17B was induced by dysregulated microbiota and that it induced lung fibrosis in a BLM-induced mouse model by interacting with TNF-α to stimulate the secretion of Th17-cell-promoting genes and neutrophil-recruiting genes (Fig. 3). The gene discussed is IL17B; the disease is pulmonary fibrosis.