SMURF1 and pulmonary fibrosis: Elkouris et al. reported that Arkadia degrades inhibitory Smad Smad7 which is methylated by Set9 and promotes bleomycin-induced pulmonary fibrosis as well as Ad-TGF-β-induced pulmonary fibrosis, whereas Smurf1/2 inhibits pulmonary fibrosis via degradation of the unmethylated Smad7-TβR complex [85] (Table 1).