RUNX3 may enhance the hydroxylation capacity of prolyl hydroxylase domain-containing protein 2 (PHD2), promote the degradation of hypoxia inducible factor-1α (HIF-1α), and weaken paraquat-induced EMT, thereby partially reversing pulmonary fibrosis (Zhu et al., 2017) (Figure 4). Here, RUNX3 is linked to pulmonary fibrosis.