SMAD2 and Bloom syndrome: Echoing the in vitro outcomes, the analysis of BLM-induced mice showed that after M-siTGF-β1 treatment, the level of TGF-β1 mRNA and protein was reduced due to RNA silencing, and the downstream phosphorylation level of Smad2/3 was subsequently reduced compared with that of the BLM-exposed mice (Fig. 8G-J).