FN1 and diabetes mellitus: Western blotting analysis suggested that the protein expression levels of transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin (SMA), fibronectin (FN), collagen I and collagen III were significantly increased in the mice with HFD/STZ-induced diabetes compared to the mice in the other two groups (Figure 1H, 1I).