CCN2 and diabetes mellitus: Diabetes‐induced cardiac fibrosis were shown via Masson's trichrome staining (Figure 4A), and fibrotic markers, including connective tissue growth factor (CTGF), transforming growth factor beta 1 (TGF‐β1), and plasminogen activator inhibitor‐1 (PAI‐1) were measured by Western blot (Figure 4B‐E).