Qin et al., 2021 showed that TET2 expression is decreased in the fibrotic lungs of mice, reaching the lowest point on the 14th day after Blm challenge. The decreased expression of TET2 is also shown in the lungs and AT2 cells of IPF patients, but TET2 in the alveolar epithelium is not involved in the progression of Blm-induced pulmonary fibrosis (Qin et al., 2021). The gene discussed is TET2; the disease is idiopathic pulmonary fibrosis.