A recent study found that the peroxisome proliferator-activated receptor-γ (PPARγ) expression was low, but increased DNMT 1/DNMT3a and PPARγ promoter hypermethylation in IPF patients; therefore, the inhibition of DNA methylation that restored PPARγ led to attenuated pulmonary fibrosis [71]. The gene discussed is DNMT3A; the disease is idiopathic pulmonary fibrosis.