SMAD2 and Bloom syndrome: The results of the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) (Figure 6g–j) showed that the expressions of TGF-β1 mRNA, Smad2 mRNA, and Smad3 mRNA in the BLM-induced rats increased significantly compared to those expressions in the normal group, while they were downregulated obviously by TRF and carotene.