Kottmann's study in 2012 showed that lactate could reduce the pH value of extracellular fluid and promote the activation of latent Transforming growth factor-β1 (TGF-β1) to TGF-β1, which could initiate the EMT process and finally progress to pulmonary fibrosis [10, 11]. The gene discussed is TGFB1; the disease is pulmonary fibrosis.