CCN2 and diabetes mellitus: Immunohistochemical staining showed that although there was no significant increase of the CTGF expression in the aorta of DM mice at 3 months of age compared to the age-matched control mice (Figure 1(b)), there was a significantly increased CTGF expression in the aorta of DM at 6 months of age compared to age-matched control mice (Figure 3(a)).